Compare and contrast single-bonded compounds and double-bonded compounds.

The main difference between single double and triple bond is the number of shared electrons. If the shared number is one pair of electrons, the bond will be a single bond, whereas if two atoms bonded by two pairs (four electrons), it will form a double bond.

Souce: pediaa.com/difference-between-single-double-and-triple-bonds/

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)