Oil is a nonpolar covalent compound. This means that the electrons in the covalent bonds between the carbon and hydrogen atoms are shared equally. The electronegativity of carbon and hydrogen is very similar, so there is no significant difference in the attraction for the electrons. This results in a nonpolar covalent bond.

Water is a polar covalent compound. This means that the electrons in the covalent bonds between the oxygen and hydrogen atoms are not shared equally. The oxygen atom has a higher electronegativity than hydrogen, so it attracts the electrons more strongly. This results in a partial negative charge on the oxygen atom and a partial positive charge on the hydrogen atoms. The polar covalent bonds in water molecules create a net dipole moment, which means that water is a polar molecule.

Ionic compounds are compounds in which the atoms are held together by ionic bonds. Ionic bonds are formed when electrons are transferred from one atom to another, resulting in the formation of positively and negatively charged ions. Ionic compounds are typically composed of a metal and a nonmetal. For example, sodium chloride (NaCl) is an ionic compound composed of sodium and chlorine ions.