What determines how many items make up a particular unit

The Avogadro's number determines how many items make up a particular unit, such that 1 mole of a substance contains 6.022 × 10^23 items.
These items may be particles such as molecules, atoms, ions , etc
Therefore, 1 mole of anything has 6.022×10^23 items.
This number is called the Avogadro's constant and applies to all substances, and is normally used by researchers and scientists to determine the number of moles of elements and compounds.

Non metal is an element or substance that is not a metal metal is a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivitymetalloid is an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. they are electrical semiconductors.

The answer is nitrogen-containing bases