What determines the atomic number of an element? a. protons b. neutrons c. electrons

The number of protons in the nucleus of an atom determines an element's atomic number. In other words, each element has a unique number that identifies how many protons are in one atom of thatelement. For example, all hydrogen atoms, and only hydrogen atoms, contain one proton and have anatomic number of 1.

Protons are your answer!
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