Question

The atomic weight of an element is 23 and its atomic number is 11. The number of proton, electrons and neutrons respectively, present in the atom of the element are
A. 11, 11, 12
B. 12, 12, 11
C. 11, 12, 11
D. 12, 11, 12

Answer 1

Hint: Atomic number is the total number of protons in the nucleus of an atom and it is represented by ‘Z’. Atoms of an element that have the same number of protons have the same atomic number and atoms of different elements have different atomic numbers. For example, all the nitrogen atoms have an atomic number of 7 whereas all the oxygen atoms have 8 protons in their nucleus and have atomic number 8.
Atomic mass is the total number of protons and neutrons in the nucleus of an atom and is represented by the ‘A’. Nucleus and protons together are called nucleons. For example, the carbon atom has 6 protons and 6 neutrons and its atomic number is 12. The number of neutrons in an atom may vary but the number of protons remains the same.

Complete step by step solution:
In the question the atomic mass and an atomic number of an element are given and using this we have to calculate the number of protons, electrons, and neutrons.
Given,
$ = 23$
Atomic mass or weight of the element
Atomic number of the element $ = 11$
We know that,
Number of protons $ = $ Number of electrons $ = $ Atomic number of the element
So, the number of electrons and protons in the element $ = 11$
Number of neutrons $ = $ Atomic mass $ - $Number of protons
$ = 23 - 11$
$ = 12$
After calculating we get the value for several protons, electrons and neutrons are 11, 11, and 12.
The element is Sodium and is represented as $_{11}^{23}Na$

So, the correct answer is Option A.

Note: 1. Electrons are negatively charged particles which move around the nucleus of an atom in an orbital. The charge of an electron is $ - 1.6 \times {10^{ - 19}}$ and its mass is $9.6 \times {10^{ - 31}}$.

2. Protons are positively charged particles which are found inside the nucleus. The charge of a proton is $1.6 \times {10^{ - 19}}$ and its mass is $1.672 \times {10^{ - 24}}$.

3. Neutrons are neutral particles that are found inside the nucleus along with protons. The mass of a neutron is $1.674 \times {10^{ - 24}}$.