Question

The nucleus of an element contains 11 protons. Its valency would be
A. 0
B. 1
C. 2
D. 3

Answer 1

Hint: A usual atom has protons, neutrons, and electrons along with other particles that exist such as alpha and beta particles. Largely the mass of an atom is in the nucleus which comprises nucleons. Nucleons contain protons and neutrons.

Complete Step by Step Answer:
The Bohr model indicates the three fundamental subatomic particles.
These are protons, electrons, and neutrons.
All the positive charge of an atom is encompassed in the nucleus and is because of the protons.
Neutrons carry neutral charges. Electrons, which have negative charges, are found outside of the nucleus.
The atom's mass is in the nucleus.
It is a little, dense area in the interior of every atom and has nucleons.
Nucleons are the combination of protons and neutrons.
The number of protons is equal to the atomic number of an element.
Here we are given an element that has eleven protons.
So, the atomic number of that element is 11.
The element is Magnesium.
Bohr proposed that electrons revolve around the nucleus in a definite circular path named shell or orbit.
These shells are named energy levels.
These shells are indicated as K, L, M, N, or numbers 1,2,3,4.
The utmost no.of electrons in each energy group is given by the formula \[2{n^2}\] where 'n' is the energy level.
So, the utmost no.of electrons in each shell is
1st orbit, K-shell = \[2 \times {\left( 1 \right)^2}\] = 2 electrons.
2nd orbit, L-shell = \[2 \times {\left( 2 \right)^2}\] = 8 electrons.
3rd orbit, M-shell = \[2 \times {\left( 3 \right)^2}\] = 18 electrons.
4th orbit, N-shell = \[2 \times {\left( 4 \right)^2}\] = 32 electrons.
Magnesium has the atomic number 11.
So, K-shell will have 2 electrons, L-shell will have 8 electrons and M-shell has 1 electron.
The electronic configuration will be 2, 8, and 1.
Hence, the outermost shell has 1 electron.
So, its valency is 1.
So, option B is correct.

Note: Protons were found by Ernest Rutherford in 1919 when he conducted his gold foil experiment. He launched alpha particles i.e., helium nuclei to gold foil. He found out that the positive alpha particles were deflected. He deduced that protons live in a nucleus and possess a positive nuclear charge. Electrons were found by Sir John Joseph Thomson in 1897. J.J Thomson did multiple experiments concerning cathode rays and indicated the ratio of mass to the electric charge of cathode rays. He later substantiated that cathode rays are basic particles and have a negative charge. These cathode rays were later known as electrons.