Question

1. identify the following examples as elemental molecules, compound molecules, or mixtures. oxygen carbon dioxide nitric acid hydrochloric acid air nitrogen

Explanation:

Step1: Recall definitions

Elemental molecules consist of atoms of the same element. Compound molecules have atoms of different elements. Mixtures contain different substances.

Step2: Analyze oxygen

Oxygen ($O_2$) has only oxygen - atoms, so it is an elemental molecule.

Step3: Analyze carbon dioxide

Carbon dioxide ($CO_2$) has carbon and oxygen atoms, so it is a compound molecule.

Step4: Analyze nitric acid

Nitric acid ($HNO_3$) has hydrogen, nitrogen, and oxygen atoms, so it is a compound molecule.

Step5: Analyze hydrochloric acid

Hydrochloric acid ($HCl$) has hydrogen and chlorine atoms, so it is a compound molecule.

Step6: Analyze air

Air contains nitrogen, oxygen, carbon - dioxide, etc., so it is a mixture.

Step7: Analyze nitrogen

Nitrogen ($N_2$) has only nitrogen - atoms, so it is an elemental molecule.

Answer:

Oxygen: Elemental Molecule
Carbon dioxide: Compound Molecule
Nitric acid: Compound Molecule
Hydrochloric acid: Compound Molecule
Air: Mixture
Nitrogen: Elemental Molecule