Which of the following are likely to form a covalent bond? aluminum and oxygen sulfur and oxygen magnesium and chlorine copper and copper

Firstly, covalent bonds are made between non-metals. In covalent bonding electrons get shared between elements in order to become stable. So you answer would therefore be sulfer and oxygen (which should form sulfer dioxide).

Hope it helps!

The answer is 1.82 j/g°c                  

Ibelieve its because the stove is a cleaner burning fuel