Which subatomic particle determines the identity of an element?

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

Answer: (C)

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. Note that neutrons are neutral particles in the nucleus and can vary in number without changing the element's identity (isotopes).
4. Recognize that electrons are negatively charged particles orbiting the nucleus and can change without altering the element's identity (ions).
5. Conclude that since the number of protons uniquely identifies an element, the proton is the subatomic particle that determines the identity of an element.