Which subatomic particle determines the identity of an element?

• A. Neutron
• B. Positron
• C. Electron
• D. Proton

Answer: (D)

Verified step by step guidance

1. Recall that the identity of an element is defined by its atomic number, which is the number of protons in the nucleus of an atom.
2. Understand that protons carry a positive charge and are located in the nucleus, and each element has a unique number of protons.
3. Neutrons, which are neutral particles in the nucleus, affect the isotope of the element but do not change the element's identity.
4. Electrons, which are negatively charged and orbit the nucleus, determine the atom's charge and chemical behavior but not its elemental identity.
5. Positrons are not subatomic particles found in atoms under normal conditions; they are the antimatter counterparts of electrons and do not determine elemental identity.