Question

1. using the isotope from the image provided, what does the number 20 mean? a the total number of neutrons in the nucleus. b total number of protons and neutrons in the nucleus. c total number of protons in the nucleus.

Explanation:

In the notation of an isotope, the lower number represents the atomic number. The atomic number is equal to the number of protons in the nucleus of an atom.

Answer:

C. Total number of protons in the nucleus.