Question

How do you find the atomic number and atomic mass?​

Answer 1

Atomic mass is the sum of the masses of protons , neutrons and electrons in an atom. But the weight of electron of an atom is always taken as no mass because of electron has very little mass. So atomic mass is the sum of protons and neutrons.

But because of isotopes atomic mass is also calculated as the average mass of every isotopes of an atom.

Answer 2

$\huge{\underline{\underline{\mathfrak{Answer}}}}$

➡️To calculate the atomic mass of a single atom of an element, add up the mass of protons and neutrons.

➡️Example: Find the atomic mass of an isotope of carbon that has 7 neutrons. You can see from the periodic table that carbon has an atomic number of 6, which is its number of protons.