Respuesta :
Answer: Protons , Neutrons , and Helium
Explanation:
The number of protons is the atomic number, and the number of protons plus neutrons is the atomic mass. For hydrogen, the atomic mass is 1 because there is one proton and no neutrons. For helium, it is 4: two protons and two neutrons.
Answer:
Answer: Protons , Neutrons , and Helium
Explanation: