Answer:
proton
Explanation:
The atoms is made from a nucleus and a electronic shell. The nucleus is composed from protons (positively charged) and neutrons (no charge). The electronic shell is defined by the presence of electrons (negativity charged).
Now a particular element is identified by the number of protons which have to be equal to the number of electrons in the electronic shell. A particular element may have the same number of protons but different number of neutrons, these are isotopes which have the same chemical properties.
