Question

what is the smallest particle of helium?
a proton
b element
c atom
d electron

Explanation:

• A proton is a sub - atomic particle within an atom, not the smallest particle of an element like helium.
• An element is a category (helium is an element), not a particle.
• An atom is the smallest particle of an element that retains the chemical properties of that element. Helium is a noble gas, and its atoms are mono - atomic (exist as single atoms).
• An electron is a sub - atomic particle within an atom, not the smallest particle of an element.

Answer:

C. atom