Question

Oxygen forms molecules made of two atoms, O2
. Carbon and oxygen form molecules made of one carbon atom and two oxygen atoms, CO2
. Which of the statements below is true?
A.
Both O2
and CO2
are compounds.
B.
Both O2
and CO2
are molecules.
C.
O2
is a compound while CO2
is a molecule.
D.
O2
is a molecule while CO2
is a compound.

Answer 1

The correct statement is:

D. O2 is a molecule while CO2 is a compound.

Here's a brief explanation:

- **O2** is a molecule composed of two oxygen atoms, but it is not a compound since it consists of only one element (oxygen).
- **CO2** is a compound because it consists of two different elements (carbon and oxygen) combined in a fixed ratio.

Therefore, option D accurately describes the classification of these two substances.