The element calcium has the atomic number of 20 and the mass number of 40, how many neutrons does it have?
February 20th, 2023
An atom of the calcium-40 isotope has ##20## neutrons in its nucleus.
are named for their mass numbers, for example, carbon-14. The of an isotope is the sum of the number of protons and neutrons in the atomic nucleus. The is the number of protons.
The calcium-40 isotope has a mass number of ##40##, and an atomic number of ##20##, therefore it has ##20## protons.
##”Number of neutrons”=”(mass number)”-“(atomic number)”##
##”Number of neutrons”=40-20=20##
