Question

The radius of an atom is approximately.

Answer 1

Hint: Before answering this question, we should know what an atom is. An atom consists of a dense core known as a nucleus. The nucleus consists of three main basic particles known as subatomic particles. The subatomic particles are electrons, protons and neutrons.

Complete answer:
An atom is the smallest yet complex unit of the matter surrounding us. These atoms combine and form an element. Each element possesses its own distinguishable chemical and physical properties. But what they have in common can be found out by looking at the structure of an atom. The outermost subatomic particle is known as an electron. These electrons are negatively charged in nature and they revolve around the nucleus in an atomic orbit. These outer electrons are also termed as valence electrons of an element. Now, looking into the inner side of the nucleus where most of an element lies, that is protons and neutrons. Protons are stable and positively charged subatomic particles whereas neutrons possess neutral charge. Protons and neutrons have almost the same mass i.e $1.67\times {{10}^{-24}}$grams whereas electrons have much lesser mass compared to protons and neutrons i.e $9.1\times {{10}^{-28}}$. Due to the less mass of an electron, it is not considered while calculating the total mass of an atom.
The half the distance between adjacent atoms of the same element in a molecule is known as atomic radius. The shortest distance between the atom’s nuclei and the outermost shell of the atom is known as atomic radius. The radius of an atom is approximately ${{10}^{-10}}$m.

Note:
The total mass of an atom is the summation of the mass of protons and the mass of neutrons. All the atoms have at least one proton in their nucleus. These protons help us to identify which element it is. For example, if we consider two elements lithium and oxygen, what they have in common is that they all consist of three subatomic particles but they differ in number. Lithium consists of 3 protons, 3 electrons, and 4 neutrons whereas oxygen consists of 8 protons, 8 electrons, and 8 neutrons.