How many sigma `(sigma)` and pi `(pi)` bonds are present in each of the following molecules?
(i) `CH_(2) = C = CH_(2)`
(ii) `CH_(3) - CH = CH - C -= C - CH_(3)`
Strategy: Every single covalent bond is a sigma`(sigma)` bond, every double covalent bond consists of one sigma `(sigma)` and one pi `(pi)` bond, and every triple covalent bond consists of one sigma `(sigma)` and two pi `(pi)` bonds.