Consider the following list of substances:

Question

carbon dioxide, CO2

hydrogen gas, H2

magnesium, Mg

sodium chloride, NaCl

methane, CH4

potassium, K

Which of the substances are compounds?

Answer 1

In the provided list, the compounds are:

1. Carbon dioxide (CO2)
2. Sodium chloride (NaCl)
3. Methane (CH4)

These substances consist of two or more different elements that are chemically bonded together.

The other substances in the list are elements or elemental forms:

• Hydrogen gas (H2) is an elemental form of hydrogen.
• Magnesium (Mg) is an elemental metal.
• Potassium (K) is also an elemental metal.

Thus, the compounds in the list are CO2, NaCl, and CH4.