Which compounds shown represent molecules containing covalent bonds?
a) calcium bromide
b)methyl bromide
c)ethylene bromide
d)potassium bromide

Methyl bromide and Ethylene bromide contain covalent bonds.

Explanation:

Calcium bromide and Potassium bromide are ionic compounds in which the cation and anion are held together by the electrostatic force of attraction.

In ionic bond complete transfer of electrons take place thus creating a cation and anion whereas electrons are shared by two atoms in a covalent bond.

Methyl bromide and Ethylene bromide are organic compounds in which every bond is a covalent bond.

This can be better understood with the help of structure of molecule which is given below.