Question

If the atomic number of an element is how many protons and electrons it has, how do you find the

number of neutrons in an atom

Answer 1

M-A=N

Step-by-step explanation:

M-A=N

Here is an example.

The equation above means that the atomic number (A) subtracted from the average atomic mass (M) equals the combined amount of neutrons and protons. Since we know that 35 17Cl is Chlorine (this is because Chlorine (Cl) is the 17th number on the periodic table and has the average atomic mass of 35), we can insert our data into the equation and end up with the following:

35-17=18.

From here, we can tell that we have 18 neutrons and 17 protons.

But we still need to find the number of electrons. Fortunately, the number of electrons is always equivilant to the number of protons and the atomic mass, so we know that the number of electrons is 17.

So, we have;

17 Protons

18 Neutrons

17 Electrons

Hope this answers your question.

Answer 2

number of neutrons in an atom = Mass number - atomic number

Step-by-step explanation:

The atomic number of an element is equal to the number of protons and electrons it has.

The mass number is equal to the total number of protons and neutrons in an element.

The mass number is also called as atomic mass number or nucleon number.

So,

number of neutrons in an atom = Mass number - atomic number