Answer:
if electrons are shared unequally between bonded atoms
Explanation:
A polar covalent bond is a bond that is formed due to the unequal distribution of electrons between two partially charged atoms. This is observed when the difference in electronegativity between the bond atoms is between 0.5 and 1.7.
A polar bond is a covalent bond between two atoms where the electrons that form the bond are unevenly distributed. This causes the molecule to have a slight electric dipole moment where one end is slightly positive and the other is slightly negative.
The charge of the electric dipoles is less than a full unit charge, so they are considered partial charges and are called delta plus (δ +) and delta minus (δ-).
Because positive and negative charges are separated at the bond, molecules with polar covalent bonds interact with the dipoles of other molecules. This produces intermolecular dipole-dipole forces between the molecules.
This link might help you!!
https://www.eiu.edu/biology/bio1500/writing_a_lab_report.pdf
The states of matter is solid,liquid and gas & you go from there.
You need to find the abundance. Then, multiply the abundance by 100, and add that to the mass for each isotope. Basically, for each isotope, take the percentage abundance and add it to the mass. Multiply each calculation of these together to get your average atomic mass,