EVERYDAY SCIENCE

Detailed explanation-1: -Together, the number of protons and the number of neutrons determine an element’s mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.

Detailed explanation-2: -The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom.

Detailed explanation-3: -Review: An element’s or isotope’s atomic number tells how many protons are in its atoms. An element’s or isotope’s mass number tells how many protons and neutrons in its atoms.

Detailed explanation-4: -Atomic mass is equal to the sum of the number proton and number neutron.

Detailed explanation-5: -The number of neutrons is represented by the neutron number (N). Because the mass of these nuclear particles is each approximately equal to one unified atomic mass unit (u), the sum of the protons plus neutrons is designated as the mass number (A).