Biography of J. Isfred Isidore Hofbauer (J. Hofbauer)

J. Isfred Isidore Hofbauer Portrait
undated photo of J. Hofbauer [1]

J. (Jsidro) Isfred Isidore Hofbauer or simply J. Hofbauer (born September 8th, 1871 in Vienna, Austria - March 13th, 1961 in Cincinnati, US) was a Austrian-born American gynecologist who performed extensive studies of obstetric organ systems and pioneered new treatments with regard to childbirth. Furthermore, he doubled as an oncologist formulating early operations to treat breast cancer. [2]

Early Life

Hofbauer was of Scandinavian and Austrian heritage. [3] His parents were Moritz Hofbauer and Jeanette Gewitsch. [4]

John's Hopkins Medical School Women's Clinic - circa 1924
Johns Hopkins Hospital Women's Clinic circa 1924. [5]

University Associations

He studied at medicine at the University of Vienna. He did his residency at the Nothnagel Clinic and the Women's Clinic at the Bettina Pavilion. He studied under Friedrich Shauta and Ernst Wertheim for his postgraduate work. He was the lead doctor in the Women's Clinic at Königsberg University from between 1906 and 1912. In 1909 he became the chair of gynecology and obstetrics at the University of Königsberg. He was invited in 1924 by John Whitridge Williams to join the faculty of Johns Hopkins University, where he served as an Associate Professor. In 1933 he moved to the University of Cincinnati where he continued to be an Associate Professor of Obstetrics and gynecologist at the Jewish and Good Samaritan Hospitals. [2,3,4]

Scientific Career

In 1896, J. Hofbauer proposed a "neuclein" treatment for severe infections about childbirth, providing a positive assessment as to its potential due to positive results in seven patients. [6] He continued to experiment with this treatment, continuing to report positive while others in the field attempted to extend the field to inoculation from disease as well. [7] Hofbauer was known to emphasize the techniques efficiency when delivered via the stomach. [7] At the time the "neuclein" was defined to be the part of blood serum left over after digestion within the stomach. [8] Although it was theorized that special "white blood cells" within the blood with phagocytic properties were responsible for the remedy for bacterial infection, this was only one of a few competing theories. [8] The injection of serum was typically accompanied by a saline solution injection and occasionally damaged the bone marrow of the patients [9]. Studies by other researchers to "inoculate" for specific bacteria with blood serum injections were unsuccessful [7].

J. Hofbauer - Biology of the Human Placenta Cover Page
Translation: Biology of the Human Placenta with a special emphasis on the question of fetal nourishment by Dr. J. Hofbauer

J. Hofbauer published a book in 1905 regarding a morphological study he conducted of the human placenta. [10] He described visible "fat cells" within the developing fetus. [11] There was also a special kind of "vacuolated" cell that he described in great detail within the book.

"Vacuolated" cells within the first Table in Appendix of J. Hofbauer's book.

In his 1925 paper entitled "THE FUNCTION OF THE HOFBAUER CELLS OF THE CHORIONIC VILLUS PARTICULARLY IN RELATION TO ACUTE INFECTION AND SYPHILIS" [12], J. Hofbauer translated his original description of the cells which would later become known as Hofbauer cells:
“These specific cells make their appearance by the end of the fourth week of pregnancy. They are comparatively abundant in the early stages of the placenta and decrease in number later on, as the connective tissue of the villus gradually assumes a more fibrous character. The duration of life of the individual cells is shown by the fact that they vanish after total vacuolization. In the cytoplasm which primarily contains homogenous or delicate granules, minute pellucid spots gradually appear about the periphery of the nucleus; later increase in size, and form a clear area surrounding it. These spaces which are filled with fluid and are separated from one another by thin septa, may fuse together, and thus give rise to larger vacuoles. Similar foam-like structures subsequently occur in the peripheral zone of the cells, as well. Furthermore, an essential part of the cytoplasm is represented by smaller and larger granules. In the beginning, these cells are intimately connected with the stroma cells of the villi and are to be considered as descendants of the original mesenchyme. Marchand holds the same view. Staining fresh placental tissue with neutral red throws the vacuolated cells into the boldest relief, while the surrounding tissue remains unstained. It is the granules and the vacuoles of the cells which take up the dye with avidity. These are the fundamental structural constituents of the cells in question, and they may play a considerable biologic part. As to their physiologic role, we can only say that they probably possess a digestive function,--a view which is supported by the presence of fat in the vacuoles, as well as of neutral red. The phagocytic power is further supported by the fact that at the stage of development, when the nucleated red blood cells lose their nuclei, I could demonstrate the disintegration of their nuclei within the fetal capillaries of the chorionic villi, and that the fragments of the nuclei were engulfed by the cytoplasm of a type of cells quite comparable in structure to our vacuolated cells. As this phenomenon could be observed distinctly in various specimens, it became obvious that our cells may bc regarded as wandering cells, which had gained access to the fetal blood stream, and thereby constituted a portion of its white cells.” 
He also included a clearer figure with stained Hofbauer cells (HBCs) exclusively within his 1925 paper, which then goes on the delineate rapid increase in the number of HBCs in response acute infection. These kinds of morphological studies were common within Hofbauer's research. This indicates that the Hofbauer cells were being seriously considered to be macrophages as early as 1924/1925. [12]

Hofbauer Cells - 1925
Fig. 1: Section through normal villus at third month, showing Hofbauer cells.

Hofbauer also found that these cells reacted in a similar manner to a certain dye as other cells within the bone marrow and Kupffer cells, foreshadowing their future similarities as tissue-resident macrophages. [12]

Advertisement for Pituitary Extract featuring a glowing review by Hofbauer. [13] 

He was also one of the first gynecologists to utilize pituitrin, an extraction from cattle pituitary hormones, in order to help deal with labor pains. By the time the advertisement above was published, Hofbauer had applied the treatment to twelve patients and stated that "there were no unfavorable after-effects." [13] He recommended the product for "all forms of primary and secondary uterine inertia," noting that the introduction of these hormones has removed the need for many once common complex surgical procedures. [14] Reflecting in 1955 within his paper, Forty Years of Postpituitary Extract in Obstetrics, Hofbauer wrote the following [15]:
THE importance of the initial impulse that a fascinating experimental observation may inspire for its application to spheres of considerable practical interest is forcefully illustrated by the mosaic of significant advances which resulted from the report by H. H. Dale of vigorous contractions of the virgin guinea pig's uterus suspended in a neutral solution, induced by the addition of post-pituitary extract. Factual background data form the basis of the present attempt of an objective evaluation of the merits of post-pituitary preparations as a therapeutic standby, while an exhaustive review of the subject is not in the scope of this survey. 
The reflection above characters much of Hofbauer's research: a kind of try-and-see approach that attempted to find success and justified the original experiments with factual evidence afterwards.

Hofbauer also attempted to connect the human pituitary gland to the origins of cancer within mothers. He saw the cancer as a continued production of growth hormone that led to increased cell division. Although he was unable to link his theory to all cancers, Hofbauer successfully utilized X-ray radiology on the pituitary to help patients which was a precursor to modern radiation treatments. [16]


Thomas F. Baskett wrote in his book, Eponyms and Names in Obstetrics and Gynaecology, that Hofbauer was "arrogant, egotistical and aggressive." Baskett recalls a story where Hofbauer told a junior colleague to write about their meeting in this manner: "Go home and write in your diary that today you talked to Hofbauer." [3]

Supplemental Image

Stained Placental Cross-Section by Hofbauer
Stained Placental Cross-Section by Hofbauer for Iron Absorption (1905)


J. Isfred Isidor Hofbauer,
Times S to TNY. Dr. Isfred Hofbauer, a Gynecologist, 89. New York Times. 1961:39.
Baskett TF. Eponyms and Names in Obstetrics and Gynaecology. 3rd ed. Cambridge University Press; 2019. doi:10.1017/9781108421706
Österreichische Nationalbibliothek, ed. Handbuch Österreichischer Autorinnen Und Autoren Jüdischer Herkunft: 18. Bis 20. Jahrhundert. DE GRUYTER SAUR; 2002. doi:10.1515/9783110949001
[Johns Hopkins Hospital Woman’s Clinic, circa 1924]. Flickr. Accessed May 28, 2020.
Company P Davis &. Nuclein Therapy. Parke, Davis & Company; 1900.
The Cincinnati Lancet-Clinic. J.C. Culbertson; 1904.
The American Journal of Obstetrics and Diseases of Women and Children. W.A. Townsend & Adams; 1903.
Hofbauer Jsidro. Grundzüge Einer Biologie Der Menschlichen Plazenta, Mit Besonderer Berucksichtigung Fragen Der Fötalen Ernährung. W. Braumüller; 1905. Accessed May 28, 2020.
Archives of Internal Medicine. American Medical Association.; 1923.
Hofbauer J. The function of the hofbauer cells of the chorionic villus particularly in relation to acute infection and syphilis. American Journal of Obstetrics and Gynecology. 1925;10(1):1-14. doi:10.1016/S0002-9378(25)90514-5
The Journal of the Arkansas Medical Society. Arkansas Medical Society.; 1912.
Therapeutic Notes. Parke, Davis & Company; 1912.
Hofbauer J. Forty Years of Postpituitary Extract in Obstetrics. American Journal of Obstetrics and Gynecology. 1955;69(4):822-825. doi:10.1016/S0002-9378(16)38084-X

TIMES WLLS to TNY. GLAND INFLUENCE TRACED IN CANCER: Cell Growth Is Linked With Pituitary Overfunction in Cases of Mothers. CHECK BY X-RAY REPORTED Medical Association is Also Told of Many Infections Laid to Sinus Trouble. New York Times. 1934:16.

Is SO2 Polar or Nonpolar?

Answer: SO2 is a polar molecule because the lone pair of electrons on the central sulfur atom cause electron-electron repulsion that forces a bent structure leading to an unequal distribution of charge throughout the molecule. 

Due to the molecules relatively strong dipole, the compound a melting point of -72˚C and a boiling point of -10˚C. This means that SO2 is a gas at standard temperature and pressure. The gas is found at low concentrations in earths atmosphere at less than 1 ppm. It features more prominently on the atmospheres of other plants. For example, Venus has an atmospheric concentration of 150 ppm SO2. It can be produced from constituent elements or sulfites. The molecule is said to have a pungent smell- similar to a just-struck match. 

SO2 Ball and Stick
SO2 Ball and Stick Diagram (one of two resonance structures). Made with Avagadro.
How is SO2 utilized in the real world?

Sulfur dioxide is most commonly utilized as an intermediate in the production of sulfuric acid. It can be used as a preservative for dried fruits and it has played an important role ini wine-making for millennia. On a chemical note it serves as an excellent reducing agent in many reactions and biochemical systems. At lower temperatures it is also utilized as a solvent. It is a major air pollutant.

Is HCl Polar or Nonpolar?

Answer: HCl is a polar molecule due to the large electronegativity difference between Chlorine (3.16) and hydrogen (2.20). This causes a region of partial positive charge on the hydrogen atom and a region of partial negative charge on the chlorine halide. 

Typically the formula HCl can refer to one of two "concepts": the compound hydrogen chloride and hydrochloric acid, the aqueous form of hydrogen chloride. The compound has a melting point of -114˚C and a boiling point of -85˚C. This means that it is a gas at standard temperature and pressure. As mentioned the compound is soluble in water but it is also soluble in slightly less polar molecules such as ethanol and acetone. It is described as having a "pungent" odor. Hydrogen chloride has an in fact quite storied history being originally discovered by alchemists in the middle ages. Today it is recommended that HCl be handled with extreme caution as HCl forms a corrosive acid when inhaled or when in contact with any part of your skin.

HCl Ball and Stick Diagram
HCl Ball and Stick Diagram. Created with MolView.
How is HCl utilized in the real world?

Basically all of the prominent uses of HCl are for hydrochloric acid. This includes removing impurities from steel, as a reagent in the production of organic products utilized in pharmaceutical manufacturing, pH control and oil processing. The acid is also present within organism's digestive tract to support the process of degrading eaten foodstuffs.

Is CF4 Polar or Nonpolar?

Answer: CF4 is a nonpolar molecule due to the symmetrical tetrahedral structure which cancels out the different electron pulls by the extremely electronegative fluorine atoms. 

As a result of its nonpolar character carbon tetrafluoride has a melting point of -184˚C and a boiling point of -128˚C. This means that the compound is a gas at standard temperature and pressure. Due to the large electronegativity difference between fluorine (3.98) and carbon (2.55), the molecule is noted for an incredibly high bond strength. This is due to the partially positive carbon giving the molecular structure some ionic character. In fact carbon-fluoride bonds are noted to be the strongest bonds in organic chemistry. Tetrafluoromethane is naturally produced when you burn any carbon compound in an atmosphere of fluorine. In industrial applications the molecule is produced by combining CCl2F2 and HF.

CF4 Ball and Stick Diagram
CF4 Ball and Stick Diagram. Created with MolView.
How is CF4 utilized in the real world?

Due to the strength of the C-F bonds the compound is very stable and will only react with extreme elements like pure alkali metals. In industry the molecule is sometimes used as a refrigerant. Therefore CF4 is sometimes called R-14. As with many carbofluorides tetrafluoromethane can be used as a plasma etchant in this case specifically on silicon derivatives. Due to the molecules higher density it can also be utilized in neutron detectors. However these same properties make the structure one of the most persistent and potent greenhouse gases. The high density also means that CF4 will crowd our regular air, leading a risk of asphyxiation in poorly ventilated spaces.

Is CH2Cl2 Polar or Nonpolar?

Answer: CH2Cl2 is a polar molecule due to the unequal distribution of charge caused by the pull of electrons from the hydrogen atoms to the chlorine atoms due to hydrogen (2.20) have a lower electronegativity than chlorine (3.16). 

As a result of strong intermolecular forces caused by its polar properties, Dichloromethane has a melting point of -96.7˚C and a boiling point of 39.6˚C. This makes the compound a liquid at standard temperature and pressure. Although the liquid form is volatile, the compound is widely utilized as a solvent. Even though it does not form a solution with water, it can dissolve a wide variety of organic compounds which is why it is utilized as a solvent. CH2Cl2 is naturally produced in wetlands by macroalgae and in volcanic eruptions; however, the majority of the compound on earth is produced by humans in industrial processes. The structure is said to have a "sweet" aroma.

CH2Cl2 Ball and Stick Diagram. Created with MolView.
How is CH2Cl2 utilized in the real world?

In addition to being used as a solvent CH2Cl2 has been applied in the food industry to decaffeinate coffees and teas. The substance due to its low boiling point can extract mechanical energy from small temperature differences. Furthermore the compound can be used to weld certain plastics together. Although it is considered the least toxic of the simple chlorohydrocarbons, dichloromethane still poses serious health risks to overexposed individuals. Products with "DCM" are generally forced to label this on their packaging. It is believed that CH2Cl2 does not impact the ozone layer because it degenerates before reaching the stratosphere.

Is CH2O Polar or Nonpolar?

Answer: CH2O is a polar molecule due to the presence of a very electronegative oxygen (3.44) on one side of the molecule inducing a partial negative charge with the hydrogens carrying a partial positive charge due to hydrogen's lower electronegativity value (2.20).

Formaldehyde has a melting point of -92˚C and a boiling point of -19˚C as a result of its polar character. This means that the compound is a gas at standard temperature and pressure. It is also very soluble within other polar compounds such as water. Formaldehyde is mostly produced by processes in the upper atmosphere which account for 90% of its natural product. Processes such as forest fires and automobile exhaust systems also contribute CH2O to the environment. This molecule has also been found in interstellar space. There are many reactions involving formaldehyde within organic chemistry.

CH2O Ball and Stick Diagram
CH2O Ball and Stick Diagram. Created with MolView.
How is CH2O utilized in the real world?

The structure is a quite common precursor to many more complex molecules, including resins and finishes. There are a wide variety of niche uses as well including as a disinfectant and in photography. The compound is considered a human carcinogen at higher concentrations although your body naturally produces and requires a certain amount of formaldehyde. Certain countries have in fact banned manufacturing and importation of CH2O. There were also incidents in the 2000s where large quantities of foodstuff were contaminated in countries like Indonesia and Vietnam where the chemical was added to extent the shelf life of products.

Is CH3Cl Polar or Nonpolar?

Answer: CH3Cl is a polar molecule due to the partial negative dipole induced around the chlorine atom due to chlorine's high electronegativity (3.16) and the partial positive charges on each of the hydrogen atoms (electronegativity for hydrogen: 2.20). 

As a result chloromethane has a melting point of -97.4˚C and a boiling point of -23.8˚C. This means that the compound is a gas at standard temperature and pressure. This gas is often produced by the sugar cane industry during the burning of waste. When released it is said to have a lifespan of one to three years before decaying in the atmosphere. It also naturally occurs in marine phytoplankton and other kinds of bacteria which have an enzyme that synthesizes CH3Cl. It also also been detected as a trace gas in the interstellar space. It is described as having a "faint-sweet" odor.

CH3Cl Ball and Stick Diagram
CH3Cl Ball and Stick Diagram. Created with MolView.
How is CH3Cl utilized in the real world?

It was originally produced in 1835 by boiling a mixture of methanol, sulfuric acid and sodium chloride. This technique is still utilized today as chloromethane is widely utilized in reactions that produce compounds containing carbon, chlorine and silicon. It used to be within refrigerants. As a result the compound is also called Refrigerant-40. However this has been discontinued since the compound is labelled as a carcinogen with the same effects to the central nervous system as alcohol.

Is HCN Polar or Nonpolar?

Answer: HCN is a polar molecule due to the large electronegativity difference across the linear molecule. The electronegativity difference between nitrogen (3.04) and hydrogen (2.20) is large enough to qualify this molecule as polar. 

As a result the molecule has a relatively high melting point of -13.3˚C and boiling point of 26˚C. This means that the compound is a liquid at standard temperature and pressure. It is able to form solutions with other polar substances such as water and ethanol. It is however extremely poisonous and flammable due to the instability of the triple bond (there are many different electrons packed into this configuration). As a result on the historical uses of hydrogen cyanide was as a chemical weapon in wartime. Today it is mainly utilized in gold and silver mining in order to purify those substances. Furthermore, it is utilized in the process of electroplating these same ions on other electrodes.

If you are interested in learning more about the lewis dot structure of HCN, feel free to check out this article.

HCN Ball and Stick Diagram
HCN Ball and Stick Diagram. Created with MolView.
Where does hydrogen cyanide occur naturally?

HCN occurs in many different places in minute concentrations which ensures relatively low toxicity. For example there is a small quantity within the pits of dried fruits such as apples, apricots and cherries. Phagocytes within the human body also naturally produce HCN when they are destroying a certain particulate. It also has been detected in Tobacco smoke. However some of the most interesting theories concern the natural occurence of HCN in space. It naturally forms in interstellar clouds as a compound of pure elements. It has also been detected in the moons of other planets such as the moon Titan.

Convert a CSV Line to a List in Scratch

Welcome back to Scratch 101! In this lesson we will be converting a line from a CSV file (comma-separated value) into a Scratch list utilizing a quick data conversion program.

Objective: Learn how to utilize conditionals, iteration, string operations and lists to convert one data type to another data type.

Final Product: The reason why CSV files are called "comma-separated" is because the data is separated by comments as shown in the screenshot below.

Example CSV file
This represents the general structure of a CSV file: the top line contains headers defining each parameter and then each line afterwards contains the data for these parameters for each subject/individual within the dataset. This kind of 2D storage is extremely important and matrices form the basis of complex data science.

Final Program GUI (Graphical User Interface).
The program you will create takes a line of "CSV-input" and splits each piece of data into a single Scratch list as shown in the screenshot above.

Graphical Template:


Testing: Here is some sample data that you can utilize to test our your program:





It's always important to utilize real testing data in order to debug your program. These sets are small enough where you could make the list yourself so you'll be able to spot any mistakes pretty quickly!

Completed ProgramLink

Is N2 Polar or Nonpolar?

Answer: N2 is a nonpolar molecule because there is no electronegativity difference across the linear structure because the molecules are identical. This means that there are no permanent dipoles within the structure. 

Nitrogen is one of the most important elements on earth since it has a wide variety of applications. Due to the nonpolar properties and relatively few electrons, the compound has a quite low melting point of -210˚C and a boiling point of -196˚C. This means that the compound is a gas at standard temperature and pressure. It makes up about 78% of earth's atmosphere. Lavoisier, who is most noted for discovering oxygen (O2),  gave the compound the name azote which is what the compound is called in many languages in the present day.

N2 Ball and Stick Diagram
N2 Ball and Stick Diagram. Created with MolView.
How is nitrogen (N2) utilized in the real world?

Although nitrogen is approx. 78% of the atmosphere, only 3% of the compounds in the human body involve nitrogen of some kind, especially amine groups. However this is enough for an entire nitrogen cycle to exist which filters these nitrogen-containing molecules through an entire cycle between earth and atmosphere. It is utilized in fertilizers for agricultural applications. Liquid nitrogen is commonly utilized as a refrigerant to keep items in especially freezing conditions. Nitrogen-containing compounds even make up the material that we know as Kevlar which is an incredibly strong and durable protective shield. There are some many ways that N2 is utilized however these applications often rely on nitrogen-containing compounds rather than pure nitrogen. Therefore this listing will end; however, we recommend checking out some of our other articles concerning carbon-compounds within the "polarity" series. Click on the "polarity" sidebar tag in order to see the whole selection!

The Lewis Dot Structure for NO2+

Lewis Dot Structure for NO2+
Created by MakeTheBrainHappy
Please find the Lewis Dot Structure for NO2+ (also known as nitronium ion) shown above. As with all other Lewis Dot Structures the bonds within the structure can be replaced by two dots. Both of the oxygen's on the ends of NO2+ contain two lone pairs of electrons and are chemically neutral. The +1 positive charge within NO2+ is present on the central nitrogen atom which is the least electronegative species in the molecule (3.04 vs. oxygen's 3.44).

The presence of this positive charge induces a quite strong attraction for the molecule as a whole to balance this out either with a negatively charged cation or with an extra electron. In fact the NO2 neutral species with an extra electron tacked onto the nitrogen is quite unique in its stability when compared to similar molecules with electrons lacking a pair. If you are interested in learning more about the reaction for forming NO2+, then I would highly recommend this recently published video lecturing on aromatic ring substitution

Different kinds of nitrated benzene rings. Source
This principle brings us to the second stable conformation of NO2+. As the Lewis Dot Structure reveals, the compound would not exist in a stable form and requires negative charge to balance it out. This can often be supplied by a negative cation such as PF6-, forming a stable nitronium salt. These salts are most often utilized in order to add NO2 species to other molecules such as the benzene rings shown in the diagram above. Researchers in that lab attempted to add NO2 species to benzene rings under different acidic conditions to understand which would be most effective at producing different results.

Is NO2+ polar or nonpolar?

If you are interested in learning more about this subject, your in luck! We've written an entire article regarding this subject: The interesting properties result from the complex interaction between its structure as determined by polarity and its status as a cation. This again goes back to the structure as elucidated by the Lewis Dot Structure for NO2+.  

The Lewis Dot Structure for CH4

CH4 Lewis Structure
Created by MakeTheBrainHappy.
The Lewis Dot Structure for CH4 is shown above. These kinds of structures can also be shown by representing each of the bonds with two dots. Each atom in the bond has a full valence, with carbon having access to eight electrons and each hydrogen having access to two (this is why hydrogen only needs two). The covalent bonds between the C and the H are similar to the ones formed between two Hs because the relatively small difference in electronegativity between carbon and hydrogen.
Tetrahedral Structure of Methane
Methane is a tetrahedron structure in 3D space. Source
This Lewis Dot Structure also explains some of the fundamental properties of this particle. Since there are no lone pairs on the central atom (or any atom for that matter) there are few dipoles created and the minimal electronegativity difference means that these bonds can essentially be treated as nonpolar covalent bonds. This means that all attraction forces inside the molecule rely on weak London Dispersion Forces which only strengthen in far larger atoms. In fact the molar mass of Methane is so minuscule that it is sometimes mentioned as a possible lifting gas because its density is less than that of air. It boils at -161˚C due to the weak intermolecular forces present and normally exists as a colorless, odorless gas at STP (Standard Temperatures and Pressures).

Methane as a Solid
Methane in a Solid State. Source
Does Methane exist in other states?

Yes- it is theoretically possible to find methane in other states of matter (liquids, solids). But it is extremely rare. Solid Methane is found in hydrates which have trapped methane in a more solid state. Scientists have also theorized that the lakes of Titan, one of the moons of Saturn, are composed of Liquid Methane. Due to the low boiling and melting points, it is rare to find these other states present.

Is CH4 an acid or a base?

Methane does not really have classic characteristics of either an acid or a base but it has been classified as a very weak acid. It will not release a hydrogen in solution but it has been shown to release a hydrogen in low-pressure gas mixtures such as the upper atmosphere. However, it should be noted that all of the different species produced in these reactions are extremely unstable.

Is it soluble in water?

No- Methane is not soluble in water because it does not have polar/strong intermolecular forces needed to break the hydrogen-bonds found in water. Therefore is is classified as insoluble. However it is soluble in less polar solutions such as ethanol and acetone to a far greater degree.

Methane from a Gas Burner Stove
Methane from a gas burner stove. Source
How do Methane Emissions affect the Earth?

This article should have more information about to answer this question. A common statistic is that methane is a greenhouse gas 84 times more potent than CO2.

Methane Cycle Diagram
Methane Cycle. Source
What are the natural sources of CH4 (methane)?

There are a wide variety of sources that contribute to the cycling of methane within the earth. In terms of natural processes there are different microbes that will either release or take in methane to utilize for cellular metabolism. Most organisms as shown in the diagram are contributing methane to the environment. The imbalance within this cycle is caused by additional methane created through the burning of biomass and fossil fuels. Ultimately these agents react within the atmosphere to form power hydroxide ion oxidizers that are able to take a hydrogen from methane (CH4) - an incredibly difficult task as discussed before in this article in the section about methane as an acid.

Is CH4 polar or nonpolar?

We've written an entire article on whether CH4 is polar or nonpolar! Feel free to check it out at this address. As with all questions of polarity, the article examines the statement in terms of the geometric configuration and then tries to see how the varying electronegativities of the different elements impact the ultimate dipole moment. The existence of many elements with extreme electronegativities within one certain molecule can also have an impact!

Methane Cycle on Mars
Methane Cycle on Mars. Source
How else can be envision the methane cycle?

Scientists have postulated that the methane cycle is also taking place currently on Mars! Although it features different players due to the variable environment and different atmospheric composition, the same principle of sinks and releases are the same. Oftentimes it is postulated that methane is broken down into carbon dioxide and other alcohols instead of remaining as a free species in the atmosphere. For sinks it is most likely held as rock within the soil with the possibility of existing microbes either consuming and releasing methane into the atmosphere!


Is SO3 Polar or Nonpolar?

Answer: SO3(2-) is a polar molecule due to the lone pair electrons at the "top" of the structure causing electron-electron repulsion and a region of partial negative charge. The resulting bent structure leads to an unequal distribution of charge rotating between the different oxygen molecules depending on which is double-bonded to sulfur and which contain single-bonds at any given moment.  

In this article we will be discussing Sulfites that contain a 2- charge as opposed to Sulfur Trioxide which relies on an expanded octet in order to complete its configuration. The latter has no charge either formal or dipole moment since it is a nonpolar molecule with a trigonal planar configuration (i.e. 120˚ between the outer molecules). The former is described by the description right above. SO3(2-) has three resonance structures with one being shown in the diagram below. The other structures move the double bond to another part of the atom with all three positions sharing this extra bond for 1/3 of the time (so each oxygen atoms theoretically has 4/3 of a bond to the central sulfur atom). Although theoretically an acid exists by combining hydrogen atoms, this has only ever been observed in the gas phase of the molecule.

SO3 Ball and Stick Diagram
SO3 Ball and Stick Diagram. Created with Avagadro.
How is SO3(2-) utilized in the real world?

Sulfites are oftentimes utilized as food additives. They occur naturally in wines, although additional sulfites may be added in order to arrest fermentation and preserve the wine for a long period of time. They may also be utilized as a preservative for other long-lasting consumables such as dried fruit. SO3(2-) oftentimes does not appear in its pure form; rather, it is added ionically-bonded to a salt such as sodium, potassium or calcium. It has been noted that there are specific allergic effects and a higher risk for those with asthma or other respiratory conditions. It is generally regulated that sulfite content be labelled on the packaging of food items. 

Library of Congress - By The People Campaign

In the Fall of 2018 the Library of Congress launched a crowdsourcing website which allowed users to create accounts to transcribe historical documents. This is an excellent and rewarding opportunity for those interested in studying the humanities as you can interact directly with hundreds of thousands of primary source documents.

Library of Congress Volunteer Responsibilities
The different responsibilities for volunteers on the website.
Volunteers transcribe, tag and review those transcriptions so that the Library of Congress can publish these on their main site to improve the metadata around certain documents. This will permit historians and researchers to more easily utilize these resources in their studies and make it easier for the general public to access since the documents will be easier to read with a helpful transcription.

There are currently sixteen different "campaigns" or themes related to women's suffrage, the civil war and even legal documents from the Spanish Empire courtesy of the Law Library of Congress. However, it is nearly guaranteed that the figure for the number of campaigns will soon be outdated given that the librarians are constantly adding in new documents for volunteers to transcribe!

Letter from Andrew Johnson to Abraham Lincoln regarding William Wallace
Letter from Andrew Johnson to Abraham Lincoln (1863)
The letter above is one of the coolest in my opinion within the collection. It is a letter from Andrew Johnson to Abraham Lincoln during the former's time as the military governor of Tennessee. It introduces a friend of Johnsons, William Wallace, to the President. When you read one these little-known documents you can imagine yourself as a historian trying to contextualize it within the time period. How do we place this letter within our understanding of the relationship between Johnson and Lincoln? To what extent does William Wallace play a role in acquainting Johnson and Lincoln? To what degree does the letter foreshadow Lincoln's eventual choice of Johnson as his running mate for the 1864 election? You can imagine yourself not just as the transcriber of a letter but as an amateur historian seeking to illuminate this letter and place it within its proper contexts.

If you are interested in this specific letter you can check it out on the transcription website here:

Letter from William Seward to Mary Todd Lincoln regarding a honor from the French Government
Letter from William Seward to Mary Todd Lincoln.
A second letter I was excited to transcribe was from William Seward, the U.S. Secretary of State, to Mary Todd Lincoln regarding the honor bestowed by French government upon the widow of the much-beloved Abraham Lincoln. This transcription added on an extra international perspective to the understanding of the different responses to Lincoln's death.

Like the other letter you can find the whole series on the Library of Congress transcription page:

This transcription is also published within the main Library of Congress archives:

Published Transcription of the Letter from William Seward to Mary Todd Lincoln.
Published Transcription of the Letter from William Seward to Mary Todd Lincoln.
And of course the medal is also available as another series for transcription! It certainly paints for a rosy picture of the relationship between France and the United States at this point in time.

Medal from the French Medal Committee issued to Mary Todd Lincoln.
Medal from the French Medal Committee issued to Mary Todd Lincoln.
It is my hope that these few examples from the hundreds of thousands available within the Library of Congress crowdsourcing site illuminate the many hidden gems within these primary source documents. If you are ready to get started, please visit the homepage of the Library of Congress - For the People campaign:

Is BCl3 Polar or Nonpolar?

Answer: BCl3 is a nonpolar molecule because the chlorine halides are spaced symmetrically around the central boron atom. This cancels out all of the different polar covalent bond pulls (i.e. between each of the boron-chlorine pairs as caused by the large electronegativity difference between boron (2.04) and chlorine (3.16). 

Although the species has zero dipole moment, the presence of an incomplete octet on this species as with other similar molecules such as BF3 and BH3 leads to an inherent instability within the different parts of the compound since Boron lacks a complete octet. This tension is exacerbated by the presence of the incredibly electronegative chlorines (3.16). This causes there to be an unequal distribution of charge within the molecule between the center and the outer edges. As a result BCl3 has a melting point of -107˚C and boiling point of 13˚C. This means that the compound is a gas at standard temperature and pressure. Due to this unequal distribution of general charge the compound is also soluble within slightly polar compounds such as ethanol of compounds with similar distribution of charge dispersals such as CCl4.

BCl3 Ball and Stick Diagram
BCl3 Ball and Stick Diagram. Created with MolView.
How is BCl3 utilized in the real world?

Many of Boron trichloride's main uses stem from its properties as a strong acid due to the incomplete octet on the central Boron atom. Since it is quite reactive as an acid, it is often utilized to refine a wide variety of metals including Aluminum, Copper and Zinc. In many of these reactions Boron is the true agent and therefore BCl3 is really a source of Boron. The gas is also reactive enough to serve as a component of certain rocket fuels. Furthermore, it is utilized in organic reactions as a reagent in the synthesis of certain organic compounds. However it is noted that the compound should be handled with care because BCl3 will react with water and certain other alcohols to form hydrogen chloride. 

Is O2 Polar or Nonpolar?

Answer: O2 is a nonpolar molecule due to the linear structure containing two identical molecules with the same electronegativity. Therefore no permanent dipole is induced in any part of the structure. 

Oxygen has rich and storied history in its discovery although ultimately its properties of combustion led to these revelations. This was due to oxygen's high electronegativity (3.44). However O2 in its pure form is small and nonpolar. As a result it has a quite low melting point of -219˚C and boiling point of -183˚C. This means that the compound is a gas at standard temperature and pressure. The atmosphere consists of approximately 21% O2.

To learn more about the lewis dot structure for oxygen, feel free to read this post. This article also discusses the importance of the oxygen revolution and the importance of oxygen within carbon cycling. 

O2 Ball and Stick Diagram
O2 Ball and Stick Diagram. Created with MolView.
How is O2 utilized in the real world?

There is an incredible variety in the functions of oxygen but its inarguably most important role is within biological organisms. Oxygen serves as the final electron acceptor in the electron transport chain and an important byproduct of photosynthesis. This permits the existence of complex life forms such as humans. This is why it makes sense that oxygen therapy is important in medical treatments. It also finds similar utilizations in low-pressure space suits for astronauts. Within industry the most common usage is in smelting iron ore to steel. It is also used in manufacturing of antifreeze, fabrics and plastics. More niche applications include welding, rocket fuel oxidation, and water treatment.

Is NO3 Polar or Nonpolar?

Answer: NO3- is based on its geometric structure technically a nonpolar molecule because the different oxygen atoms are dispersed in a symmetrical manner around the central nitrogen atom. However the presence of extra lone pair electrons on two of the oxygens induces regions of partial negative charge on those oxygen atoms. 

Although nitrogen trioxide (NO3) exists, it is so unstable that it has never been isolated in pure form and theoretically only serves as an intermediate in certain reactions. Therefore we will continue this discussion by focusing on the nitrate (NO3-) ion. Within this structure the nitrogen atom has a +1 charge whereas the three oxygen atoms have partial -2/3 charge. The diagram shown below exhibits one possible resonance structure: the second bond will continuously switch b/t the oxygen atoms and end up spending approximately one-third of its time with each. In this manner a partial bond is formed with each oxygen atom. Nitrates commonly form a wide variety of inorganic salts with an ionic character containing many different metal elements. Examples include KNO3 and Fe(NO3)3.

NO3 Ball and Stick Diagram
NO3 Ball and Stick Diagram. Created with Avagadro.
Where is NO3- commonly found in the real world?

There are a wide range of nitrate sources. It is found in our diets via green foods and cured meats. The salt is present within the earth in relatively high concentrations again in salt form. Indeed some bacteria have even evolved to utilize NO3- as a food source. Within industrial uses nitrates feature prominently as fertilizers in agriculture. They are deemed not toxic but there is a small risk of nitrates degrading to nitrites (NO2-) which are a possible carcinogen.

Is NO2 Polar or Nonpolar?

Answer: NO2 is polar molecule due to the presence of a lone pair of electrons whose electron-electron repulsion results in a bent structure. This unequally distributes charge within the molecule and thereby induces a permanent dipole. 

Due to the presence of only one lone pair of electrons on the central nitrogen as opposed to for example H2O with two lone pairs on the central oxygen, we find that NO2 has a larger central angle nearly 30˚ greater than H2O's "bent" structure. This combined with nitrogen dioxides electronegative oxygen atoms (3.44) on the ends decreases the dipole moment significantly. As a result NO2 has a melting point of -9.3˚C and a boiling point of 21˚C. It is soluble in less polar compounds like CCl4 and chloroform. It is said to have a "reddish-brown" color at higher temperatures.

NO2 Ball and Stick Diagram
NO2 Ball and Stick Diagram. Created with Avagadro.
How is NO2 utilized in the real world?

Nitrogen dioxide finds use in a wide variety of reactions to product for example nitric acid or nitrites. It has also found use in rocket fuels since it is a strong oxidizer having a strong affinity for electrons. However these same properties make the compound toxic to human health as the molecule will react in the respiratory system. This has been associated with an increase in asthma cases. The 2000 census indicated that half of U.S. households use gas stoves which increase threefold the risk of NO2 poisoning.

Is CHCl3 Polar or Nonpolar?

Answer: CHCl3 is a polar molecule due to the large electronegativity difference between hydrogen (2.20) and chlorine (3.16). This induces a permanent dipole across the molecule with a partial positive charge on the hydrogen atom and a partial negative charge on the chlorine atoms. 

Since the one hydrogen on the structure (2.20) is outnumbered by three very electronegative chlorines (3.16), chloroform has a quite strong dipole moment. As a result the molecule has a melting point of -64°C and a boiling point of 61°C. This means that the compound is a liquid at standard temperature and pressure. While it is not incredibly soluble in water, it has much higher solubility in less polar solvents such as alcohol. The molecule is produced naturally by many kinds of seaweed and fungi.

CHCl3 Ball and Stick Diagram
CHCl3 Ball and Stick Diagram. Created with MolView.
How is CHCl3 utilized in the real world?

Chloroform is utilized a solvent for a wide variety of materials including fats and rubbers. It also provides -CCl2 groups in reactions. Historically it was utilized as an anesthetic but it was abandoned in the early 1900s since many persons experienced cardiac arrest as a side effect. It has been labelled a "hazardous" material and possible carcinogen. It is recommended that one limit exposure whenever possible. 

Is PCl3 Polar or Nonpolar?

Answer: PCl3 is a polar molecule due to the presence of a lone pair of electrons at the top of the molecule leading to electron-electron repulsion. This results in a bent structure that thereby unequally distributes charge throughout the molecule inducing a permanent dipole. 

In a similar manner as SF4 the more electronegative chlorine atoms (3.16) remove the effect of the lone pair on the dipole moment. However since chlorine is not as electronegative as fluorine this effect is not as extreme. Therefore phosphorus trichloride has a melting point of -94°C and a boiling point of 76°C. This means that the compound is a liquid at standard temperature and pressure. It is likewise a toxic liquid as it is volatile and will quickly react with water or water vapor. Extreme caution is recommended when handling.

PCl3 Ball and Stick Diagram
PCl3 Ball and Stick Diagram. Created with MolView.
How is PCl3 utilized in the real world?

Phosphorus trichloride is an important precursor molecule for many other organophosphorus compounds that serve as herbicides or insecticides in addition to many other specific applications. It can also be utilized in chemical reactions in order to add just chlorine to different structures such as alcohols. The molecule can act as both an acid and a base, producing many different strong and weak acids such as hydrochloric acid. At the same time, the lone pair electron permits PCl3 to act as a base and serve as a proton-acceptor.

Is SF4 Polar or Nonpolar?

Answer: SF4 is polar due to the presence of a lone pair of electrons leading to electron-electron repulsion and thereby a region of partial negative charge. However due to the other atoms in the structure being the very electronegative fluorine the partial charge on the sulfur will be quite de minimis.   

Sulfur tetrafluoride due to the effect mentioned above has a relatively low melting point of -121°C and boiling point of -38°C. This means that the compound is a gas at standard temperature and pressure. Due to the large amount of fluorine atoms it will react quite violently with water or water vapor. This makes the gas quite corrosive and toxic for humans, generating hydrogen fluoride and sulfur dioxide within the lungs. It is recommended that humans never be exposed to this molecule.  

SF4 Ball and Stick Model
SF4 Ball and Stick Model. Created with MolView.
How is SF4 utilized in the real world?

The most common usage of sulfur tetrafluoride is in creating compounds that require the addition of fluorine atoms. Specifically the combination between alcohols and SF4 typically produces many different kinds of fluorocarbon compounds. These in turn have their own specific pharmacological and industrial applications. This is similar to the kinds of applications for other compounds with a large number of fluorine atoms including NF3 and SF6