What is a compound?

What is a compound?

• A. A pure substance made up of a single element.
• B. A pure substance made up of two or more elements combined in a defined ratio.
• C. A mixture of two or more compounds.
• D. An element that can combine with others.

Answer: (A)

A compound is a pure substance formed when two or more elements are chemically bonded in a definite, fixed ratio. The bonding creates a new substance with properties distinct from its elements, and the ratio of elements is constant for that compound. For example, water is H2O, with two hydrogen atoms combining with one oxygen atom in a specific ratio; salt is NaCl, with one sodium and one chloride in a fixed ratio. In contrast, an element is a pure substance consisting of only one kind of atom, and a mixture is a blend of substances that are not chemically bonded and can have varying proportions. So the correct description points to a substance made from multiple elements bound together in a defined proportion.

A compound is a pure substance formed when two or more elements are chemically bonded in a definite, fixed ratio. The bonding creates a new substance with properties distinct from its elements, and the ratio of elements is constant for that compound. For example, water is H2O, with two hydrogen atoms combining with one oxygen atom in a specific ratio; salt is NaCl, with one sodium and one chloride in a fixed ratio. In contrast, an element is a pure substance consisting of only one kind of atom, and a mixture is a blend of substances that are not chemically bonded and can have varying proportions. So the correct description points to a substance made from multiple elements bound together in a defined proportion.