Question

What do you mean by isotopes and isotones? Give their examples.

Answer 1

Hint: Let us take carbon (C) to explain isotopes and potassium (K) and chlorine (Cl) to explain isotones. And remember that the atomic number of elements is equal to the number of protons.

Complete step-by-step answer:

As we know that neutrons of the atom are those substances (particles) that are neutrally charged.
Protons are those particles of an atom which are positively charged is also the atomic number of that element.
And electrons are the negatively charged particles of the atom.
An atomic mass of an element is the sum of protons and neutrons in that element.
And in an atom a nucleus is present at the centre of the atom and neutrons and protons are inside the nucleus.
Now according to the definition of isotopes we can say that
Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom.
And, any of two or more species of atoms or nuclei that have the same number of neutrons are known as isotones.
So, now we have to give the examples of Isotopes and isotones.
As isotopes are the different versions of the same element. So, isotopes of carbon element are
\[{}^{12}{{\text{C}}_6},{\text{ }}{}^{13}{{\text{C}}_6}{\text{ }},{\text{ }}{}^{14}{{\text{C}}_6}\]. Mass of all the elements of the carbon and their atomic number is equal. So, their neutron must be different. Hence, they are the isotopes of carbon.
Now as we know that chlorine has atomic 17 and in general it has 18 neutrons \[{}^{35}{\text{C}}{{\text{l}}_{17}}\]. But chlorine also has isotopes in which 20 neutrons are present \[{}^{37}{\text{C}}{{\text{l}}_{17}}\]..
The atomic number of potassium is 19 but the atomic mass of potassium is 39. So, Potassium must have 39 – 19 = 20 neutrons (\[{}^{39}{{\text{K}}_{19}}\]).
So, we can say that \[{}^{37}{\text{C}}{{\text{l}}_{17}}\] and \[{}^{39}{{\text{K}}_{19}}\] are isotones because in \[{}^{37}{\text{C}}{{\text{l}}_{17}}\] has 17 protons and 20 neutrons and \[{}^{39}{{\text{K}}_{19}}\] has 19 protons and 20 neutrons. So, they both have the same number of neutrons.

Note: Whenever we come up with this type of problem then to check whether the given elements are isotopes or isotones. We have to find, number of protons and neutrons in the given element. We subtract the atomic mass of that element with its atomic number because we know that the atomic mass of any element is the sum of protons and neutrons and the number of protons is equal to the atomic number of elements.