919Mechanical EngineeringMedium
The mass number of a substance represents the sum of total number of________?
Aprotons and neutrons in a nucleus
Bprotons and electrons in an atom
Cprotons and neutrons in an atom
Dneutrons and electrons in an atom
Eprotons and electrons in a nucleus
Correct answer
A. protons and neutrons in a nucleus
Explanation
The correct answer is protons and neutrons in a nucleus.