Carbohydrates contain the elements and

Carbon, Hydrogen, and Oxygen

Explanation:

Carbohydrates contain 3 elements. They are Carbon, Hydrogen, and Oxygen. Carbo means carbon and hydrate means water which is made from hydrogen and oxygen.

Hope this helps!

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds