A certain atom has 26 protons, 26 electrons, and 30 neutrons. It mass number is?

Answer : The mass number is 56.

Explanation:

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons = 26 + 30 = 56

Atomic number is defined as the number of protons or number of electrons that are present in an atom.

Atomic number = Number of electrons = Number of protons = 26

Hence, neutrons and protons affects the mass number and thus the mass number will be 56.

The most common atom of iron has 26 protons and 30 neutrons in its nucleus. What are its atomic number, atomic mass, and number of electrons if it is electrically neutral? This atom has atomic number 26, atomic mass 56, and has 26 electrons.