AP BIOLOGY

Detailed explanation-1: -Covalent molecules made of only one type of atom, like hydrogen gas (H2), are nonpolar because the hydrogen atoms share their electrons equally.

Detailed explanation-2: -Answer: NH2 is a polar molecule due to the presence of lone pair electrons which result in a bent structure thereby causing an unequal distribution of charge within the molecule.

Detailed explanation-3: -A non-polar covalent bond is a type of chemical bond that is formed when electrons are shared equally between two atoms. Thus, in an atom, the number of electrons shared by the adjacent atoms will be the same. The covalent bond is also termed as nonpolar because the difference in electronegativity is mostly negligible.

Detailed explanation-4: -The entire molecule of hydrogen sulphide is nonpolar because it is made up entirely of non-polar $ H-S $ bonds.