How do you find the mass number on a periodic table?

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.

What is the mass number of an element?

mass number, in nuclear physics, the sum of the numbers of protons and neutrons present in the nucleus of an atom.

What is the mass number of C 12?

a carbon-12 atom has 6 protons, 6 neutrons, and 6 electrons, so its mass number is 12 and its atomic number is 6 .

What is mass number example?

(ii) Mass number: It is the sum of the number of neutrons and the number of protons. For example, the atomic number of Lithium is 4 which is equal to the number of protons, the number of neutrons of magnesium is 4. The mass number is equal to 8(4+4).

How do you find mass from mass number?

For any given isotope, the sum of the numbers of protons and neutrons in the nucleus is called the mass number. This is because each proton and each neutron weigh one atomic mass unit (amu). By adding together the number of protons and neutrons and multiplying by 1 amu, you can calculate the mass of the atom.

Which is mass number?

The mass number of an atom is its total number of protons and neutrons. Atoms of different elements usually have different mass numbers , but they can be the same.