Question

What is an atom and ion of the isotope of sodium \[^{23}N{a_{11}}\] both contain?
A) $11$ electrons
B) $12$ neutrons
C) $23$ protons
D) $23$ neutrons

Answer 1

Hint: We have to know that the isotopes are atoms of the same element that have different numbers of neutrons but the same number of protons and electrons. The difference in the number of neutrons between the various isotopes of an element means that the various isotopes have different masses.

Complete answer:
We need to know that the sodium atom and sodium ion contain the same number of protons and same number of neutrons. Number of protons is equal to the atomic number and the number of electrons is also equal to the atomic number. Mass number represents the difference between atomic number and number of neutrons.
\[^{23}N{a_{11}}\]
As we know , $23$ is the mass number while $11$ is the atomic number. So the number of protons and number of neutrons is equals to $11$ while the mass number is $23$, so we have number of protons that is $11$ in this case so number of neutrons can be easily identified by using the formula of mass number so number of neutrons is equal to $12$.

So, the correct answer is “Option B”.

Note:
We need to remember that in an atom, the protons and neutrons are present inside the nucleus in an atom while electrons revolve around circular orbits that are outside the nucleus in an atom. We need to know that the isotopes of an element share the same number of protons but have different numbers of neutrons. Let's use carbon as an example. There are three isotopes of carbon found in nature – carbon-$12$, carbon$ - 13$, and carbon$ - 14$.