Question

What are the particles whose number you can find out if you know the atomic number of an atom?

Answer 1

Hint: We have to remember that the structure of an atom can be represented as: An atom contains a nucleus in which protons and neutrons reside whereas electrons reside outside the nucleus.

Complete answer:
Let us study briefly about an atom. An atom is the smallest unit of any matter. Matter can be solid, liquid or gases. The size of an atom is approximately 100 pm. Every atom contains a nucleus and nucleus further contains subatomic particles that are protons and neutrons. Number of protons is equal to the atomic number of an atom or element. An atom is surrounded by certain orbits at which electrons revolve. Number of electrons is equal to the atomic number of an atom or element. An element is a species that contains the same atoms.
For Example -\[Cl\],\[Fe\].
An atom has a given mass which is approximately equals to mass number which can also be defined as twelfth of the mass of free neutral atom of $C - 12$ i.e. approximately \[1.66 \times {10^{ - 27}}kg\].Since protons and neutrons are heavy therefore they are present at the centre of an atom whereas electrons being lightweight moves at the orbits outside an atom. Protons are positively charged particles; electrons are negatively charged particles whereas neutrons are uncharged species.
Answer- Number of protons is equal to the atomic number of an atom or element.

Note:
We have to know that the protons and neutrons are present in the nucleus which is present at the centre of an atom and an electron revolves in a circular path around an atom which is called as orbits. Neutrons are neutral species that do not contain any charge.