Question

which of the following is a correct pairing of particle type and name?
covalent compound - formula unit
ionic compound - ion
charged particle - molecule
element - atom

Explanation:

• A covalent compound is made up of molecules, not formula units. Formula units are for ionic compounds.
• An ionic compound is composed of ions (cations and anions), but the pairing here is too general as ionic compound - ion is not the most specific correct pairing compared to element - atom.
• A molecule is a neutral particle (in most common cases, like in covalent compounds), not a charged particle. A charged particle can be an ion.
• An element is a pure substance that cannot be broken down into simpler substances. The basic unit of an element (in the case of metals, noble gases, etc.) is an atom. For example, the element sodium (Na) is made up of sodium atoms.

Answer:

element - atom