Answer the following question: Answer the following question given this paragraph: The atomic number is the number of protons in an atom. This number is unique for atoms of each kind of element. For example, the atomic number of all helium atoms is 2. Q: The number of protons in an atom is called what? A:

Select from:
[a]. mass number
[b]. metallic number
[c]. isotope
[d]. atomic number
Answer:
[d].