# What isotope has 18 protons and 22 neutrons?

Feb 4, 2016

This a neutral atom of $A r g o n$.

#### Explanation:

Always remember that the number of protons represent the Atomic no. of that particular element.

In this case the number of protons is $18$,So,the atomic no. is also $18$.

And the element with atomic no. $18$ is $A r g o n$ with symbol $A r$

Now we need to find the mass number of $A r g o n$ .
Because $M a s s$ $n$$u m b e r - A t$$o m i c$ $n$$u m b e r$$=$$N$$o$ $o f$ $n$$e u t r o n s$

Mass number of Argon=$40$

No of Neutrons$= 40 - 18 = 22$

A neutral atom of argon also has $22$ Neutrons.

So,It is clear that this is not an isotope but a neutral atom of $A r g o n$