Question

A model of an atom which contains 24 electrons, 25 protons and 26 neutrons has some of its particles inside a nucleus at the centre of the model. What is the nucleon number (mass number) of the atom?​

Answer 1

The mass number of an atom with 25 protons and 26 neutrons is 51, which is the sum of the protons and neutrons in its nucleus.

Step-by-step explanation:

The nucleon number, or mass number (A), of an atom is the sum of the number of protons (p+) and neutrons (n) in its nucleus. In the model of an atom that contains 25 protons and 26 neutrons, the mass number is calculated as follows:

mass number A = (number of protons) + (number of neutrons)

mass number = 25 + 26 = 51

Therefore, the mass number of the atom is 51.

Answer 2

The nucleon number of given atom = 51

Step-by-step explanation:

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.

The mass number is also called nucleon number.

The nucleon number of given atom = number of protons + number of neutrons

The nucleon number of given atom = 25 + 26

The nucleon number of given atom = 51