Question

Complete the following.

Sl. No	Name of the element	Symbol	Mass number	Atomic number	Number of protons	Number of electrons	Number of neutrons
1	____	${}_9{}^{19}\mathrm{F}$	19	___	___	____	____

Answer 1

Definition of atomic number.

Atomic number is defined as the number of protons present inside the nucleus of an atom.

Atomic number = number of protons = number of electrons

Definition of mass number.

Mass number is defined as the sum of number of protons and number of neutrons present inside the nucleus of an atom.

Mass number = number of protons + number of neutrons.

The given symbol ${}_9{}^{19}\mathrm{F}$ and mass number =19

Atomic number = number of protons = number of electrons

Atomic number = 9

Therefore number of proton = number of neutron = 9

Mass number = number of protons + number of neutrons.

Therefore number of neutron = 10

Sl. No	Name of the element	Symbol	Mass number	Atomic number	Number of protons	Number of electrons	Number of neutrons
1	Fluorine	${}_9{}^{19}\mathrm{F}$	19	9	9	9	10