Question

question 16 (2 points)
a combination of two or more atoms joined by a bond is
an isotope
a molecule
a quark
an ion
an atomic unit

Explanation:

An isotope is a variant of an element with a different number of neutrons. A quark is a fundamental particle. An ion is an atom or molecule with a net electric charge. An atomic unit is a system of units. A molecule is defined as a combination of two or more atoms joined by a chemical bond.

Answer:

B. a molecule