Question

what is an atom?

○ a mixture of elements
○ the smallest unit of an element that retains its properties
○ a type of chemical reaction
○ a group of molecules

Explanation:

• Option 1: A mixture of elements is incorrect as an atom is not a mixture.
• Option 2: By definition, an atom is the smallest unit of an element that retains the chemical properties of that element.
• Option 3: An atom is not a chemical reaction.
• Option 4: A group of molecules is incorrect as an atom is a single unit, not a group of molecules.

Answer:

B. The smallest unit of an element that retains its properties