# How many neutrons are found in one atom of ""^36Cl?

##### 1 Answer
Aug 17, 2016

The number of neutrons in an atom of $\text{^36"Cl}$ is $19$.

#### Explanation:

The symbol $\text{^36"Cl}$ is the nuclear notation for chlorine-36, which is the mass number, $\textcolor{red}{\text{A}}$, for this particular chlorine isotope. The mass number is the sum of the protons and neutrons in the atomic nuclei of an isotope.

$\textcolor{red}{\text{Z")+color(purple)("N")=color(blue)("A}}$

You can determine the number of protons in a chlorine atom by looking it up on the periodic table, where you will see that its atomic number, $\textcolor{red}{\text{Z}}$, is $17$.

The number of neutrons, $\textcolor{p u r p \le}{\text{N}}$, in an isotope of an element is the difference between the mass number and atomic number.

$\textcolor{b l u e}{\text{A")-color(red)("Z")=color(purple)("N}}$

color(blue)(36)-color(red)(17)=color(purple)(19)"

The number of neutrons in an atom of $\text{^36"Cl}$ isotope is $19$.

You can write the symbol for the isotope chlorine-36 in nuclear notation (also called isotopic notation) as follows.

$\text{_17^36"Cl}$

You can subtract the bottom number from the top number to determine the number of neutrons