Question

How can atomic number and mass number be used to find the number of protons, electrons, and neutrons?

Answer 1

Hint: In an atom, we know that the number of protons and electrons are equal and is equal to the atomic number of an atom. The nucleus of the atom accounts for the atomic mass of the element and it contains proton and neutron.

Complete answer:
- Atoms of each element consist of a particular number of protons.
- Protons are positively charged species that possess a charge of +1. Electrons are negatively charged species with the charge of -1. Neutrons are the neutral charged particles.
- Atomic number is equal to the number of electrons and protons there in an atom. On the other hand, the number of neutrons for a given element can differ. Together, the number of protons and the number of neutrons dictates an element’s mass number.
- In order to calculate the number of neutrons in an atom, we can simply deduct the number of protons, or atomic number, from the mass number.
- Hence, we can say that the number of protons and electrons are equal to the atomic number. Atomic numbers can be identified by looking at the atom. Also, the number of neutrons is simply the subtraction of atomic number and mass number.

Note:
It is not necessary that the number of protons and neutrons will be equal in an atom. In many cases it is true but cases like sodium have a number of neutrons which are not equal to the proton.