What characteristic of an element’s atoms always determines the element’s identity?

Number of protons

Explanation:

There are three sub atomic particles. These are;

- Protons

- Electrons

- Neutrons

Among these three particles, only one determines the identity of the element. This is the Protons. The number of protons which is also called the atomic number determines the identity of an element. For instance, atom with one proton is Hydrogen and n other element can have atomic number of one.

it takes on an electronical energy