A(n) _____ refers to two or more atoms held together by covalent bonds.

• A. crystal lattice
• B. alloy
• C. molecule
• D. ion

Answer: (C)

Verified step by step guidance

1. Understand the definition of the terms given: a crystal lattice is a repeating three-dimensional arrangement of atoms or ions in a solid; an alloy is a mixture of two or more metals; an ion is an atom or molecule with a net electric charge due to loss or gain of electrons.
2. Recall that a covalent bond is a chemical bond formed by the sharing of electron pairs between atoms.
3. Recognize that when two or more atoms are held together by covalent bonds, they form a distinct chemical entity called a molecule.
4. Therefore, the term that refers to two or more atoms held together by covalent bonds is 'molecule'.
5. Confirm that the other options do not fit this definition, making 'molecule' the correct choice.