Which is true about the compounds carbon monoxide (CO) and carbon dioxide (CO2)? A. The compounds have the same properties because they contain the same elements.

B. The compounds have different properties because they are found in different amounts in the atmosphere.

C. The compounds have the same properties because they are both gases.

D. The compounds have different properties because they contain the same elements in different quantities.

D. The compounds have different properties because they contain the same elements in different quantities.

Explanation:

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass. It can be decomposed into simpler constituents using chemical reactions.  

contains carbon and oxygen in the ratio of 3: 4 by mass whereas contains carbon and oxygen in the ratio of 3: 8 by mass.

The physical properties of two different compounds are different as they contain same elements but the elements are present in different ratios.

it is stable as it is in group 0 which have full outer shells of electrons