12.
Contrast and compare:
a) ionic and covalent bonding

Ionic bonds - an intramolecular force exist in a nonmetal and metal compounds such as NaCl. The Na donate 1 electon to Cl to complete its octet rule.

Covalent bond - an intramolecular force exist in a nonmetal and nonmetal compounds such as bonds O2, Cl2, CO2, sugar, proteins and most of organic compounds and biomolecules by sharing electrons to bond.

There are two types of covalent bonds: polar and nonpolar. Polar bond is a bond between two different nonmetal atoms of different electronegativities. While nonpolar bond is a bond between the same atom or two differenct atoms of the same electronegativities (if there is). Their electronegativities pull will cancel so that their overall polarity is zero.

lol for the pointsss

level 4 to level 2 : ))