Is Cl2 Polar or Nonpolar?

Answer: Cl2 is a nonpolar molecule because the two molecules in the linear structure are identical. Therefore they have the same electronegativity and no permanent dipole is established. 

Although the molecule has a larger number of electrons and can form relatively strong temporary forces (London dispersion forces), the lack of a dipole moment means that the molecule has a low melting point of -102°C and boiling point of -34°C. This means that chlorine is a gas at standard temperature and pressure. Due to the large electronegativity of chlorine (3.16), Cl2 is a strong oxidizer with an affinity for electrons. It is therefore capable of forming an entire class of molecules including ionic compounds.

One of the most well known ionic compounds is table salt, also known as NaCl. Feel free to learn more about the polarity of this truly ancient compound. 

Cl2 Ball and Stick Model. Created with MolView.

How is Cl2 utilized in the real world?

Chlorine has a wide variety of applications but most of it is consumed in reactions that produce other chlorine compounds. This occurs because Cl2 is the most abundant chlorine-containing molecule available on the entire earth. These products have an extremely diverse number of uses. The structure as found natively is utilized as a disinfectant. This is most popularly known as "chlorination" in public pools - this is what you find in many pools and other public bathing spaces. Due to its high oxidizing properties it is quite toxic towards human health. This is why the compound has been utilized in certain warfare applications. Furthermore, it will have an effect on human health because the chlorine anion is involved in a wide variety of different biological feedback regulation mechanisms.