Which term describes a substance made of atoms of two or more different elements that are chemically combined?

• A. Element
• B. Mixture
• C. Solution
• D. Compound

Answer: (D)

When two or more different elements join together by chemical bonds in fixed proportions, they form a substance with properties different from the elements themselves. This is what a compound is. A compound describes substances that are chemically bonded and have a definite ratio of elements, which is why it’s the best term here. An element is pure and contains only one type of atom. A mixture results from simply mixing substances without bonding, so the components can usually be separated by physical means and their proportions can vary. A solution is a type of homogeneous mixture where a solute is dissolved in a solvent, not necessarily involving chemical bonding between the components. Water is a compound made from hydrogen and oxygen; air is a mixture; salt dissolved in water is a solution.