Question

Classify each of the following as an element, a compound, or a mixture:

a) Oxygen gas
b) Saltwater
c) Gold jewelry
d) Carbon dioxide

Answer 1

Oxygen gas is an element, saltwater is a homogeneous mixture, gold jewelry can be a mixture but is an element if pure gold, and carbon dioxide is a compound.

Step-by-step explanation:

Classifying substances into elements, compounds, and mixtures helps us understand their composition and properties. Here is the classification for each given substance:

• Oxygen gas (O2) is an element because it consists of only one type of atom.
• Saltwater is a homogeneous mixture (solution) because it consists of salt (sodium chloride) dissolved evenly in water.
• Gold jewelry is often a mixture, as it may contain different metals besides gold. However, if the jewelry is pure gold (24 karat), then it is an element.
• Carbon dioxide (CO2) is a compound because it is made of carbon and oxygen atoms in a fixed ratio.