Which term defines the simplest form of matter that has unique chemical properties?

• A. Molecule
• B. Compound
• C. Atom
• D. Element

Answer: (D)

Verified step by step guidance

1. Understand the definitions of the given terms: An atom is the smallest unit of an element that retains the properties of that element; a molecule is two or more atoms bonded together; a compound is a substance made of two or more different elements chemically combined; an element is a pure substance consisting of only one type of atom with unique chemical properties.
2. Recognize that the question asks for the simplest form of matter with unique chemical properties, which means it should be the most basic unit that still exhibits those properties.
3. Recall that an element is defined as a pure substance made up of only one kind of atom, and it cannot be broken down into simpler substances by chemical means while retaining its chemical properties.
4. Note that while atoms are the smallest units of elements, the term 'element' refers to the substance as a whole, characterized by unique chemical properties determined by its atoms.
5. Conclude that the correct term describing the simplest form of matter with unique chemical properties is 'Element'.