carbon dioxide, or [tex] CO_{2} [/tex], is a pure covalent bond.
pure - it's non-polar, because it's a linear & symmetrical bond.
covalent - covalence is when 2 electrons are shared by a pair of atoms. in the case of carbon dioxide, it's three atoms with an oxygen atom on the right, an oxygen atom on the left, and a carbon atom smack in the middle. 2 of carbon's extra electrons are shared with the right oxygen, and 2 other extra atoms are shared with with left oxygen.
