Question

What does atom mean?
A) Smallest unit of any matter
B) Tiny indivisible particle
C) An atom contains subatomic particles
D) All of the above

Answer 1

We have to remember that the neutrons, protons and electrons are the units that are present in an atom. Protons and neutrons have approximately equal mass whereas the number of protons and electrons are equal in an atom.

Complete step by step answer:
We have to know that 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 electron revolves.
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.
Option A) this option can be correct as an atom is the smallest unit of any matter, but we also have other options.
Option B) This option can be correct as an atom is a tiny indivisible particle, but we also have other options.
Option C) this option can be correct as an atom contains subatomic particles which are electrons, neutrons and protons, but we have other options too.
Option D) this is a correct option as all the options above are correct thus this option is right which says All of the above.

Hence, the correct answer is ‘Option D’.

Note: We have to remember 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 an orbit.