Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.

The wheels are causing less friction between the ground and the box. In order to push it, less force is needed.

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.