Question

the atomic number of fluorine is 9 and its atomic masses 19 what is the number of neutrons present in the nucleus

Answer 1

Atomic number of Fluorine = 9
Atomic mass of Fluorine = 19

We know that the number of neutrons in atomic mass is the remaining particles left after excluding the protons in it.

Hence,

Number of neutrons in an atom of Fluorine = Atomic Mass - Atomic Number

Number of neutrons in an atom of Fluorine = 19 - 9 = 10

Answer 2

10 neutrons

Atomic mass= no. of nucleons

So, no. of neutrons=no. of nucleons-no. of protons.

=19-9

=10