In sulphur trioxide(SO3) there are how many oxygen atoms and how many sulfur atom's.

If you have the formula correct, then it looks like 1 Sulfur and 3 Oxygen

The prefix "tri-" might give a clue, too. What does it mean? Does it mean four, twelve, 1,001?

To determine the number of oxygen atoms and sulfur atoms in a molecule of sulphur trioxide (SO3), we need to look at the chemical formula.

The chemical formula SO3 indicates that there is 1 sulfur atom (S) and 3 oxygen atoms (O) in one molecule of sulphur trioxide.

Sulphur trioxide is made up of one sulfur atom (S) and three oxygen atoms (O), resulting in the chemical formula SO3.