Which two values are protons used to determine in elements?

Protons are used to determine the atomic number and the mass number in elements.

Explanation:

Atomic number can be described as the number of protons present in the nucleus of an atom. The different number of protons present in the nucleus of an atom distinguishes one atom from another. For example, hydrogen has a single proton so the atomic number of hydrogen is one.

The mass number can be described as the total number of protons and neutrons present in the nucleus of an atom. For example, Lithium has 3 protons and 4 neutrons so the atomic number for Lithium is 7.