Question

A certain species X has 17 protons, 18 electrons and 20 neutrons.

(i) What is such a particle called? 

(ii) What is the mass number of X? 

(iii) What is the atomic number of X?

Answer 1

Number of protons in species X = 17 

Electrons = 18 

Neutrons = 20

(i) The particle is called an ion because of the more number of the electrons in the atom. There will be a negative charge on the atom due to more electrons, these type of ions are called anions.

(ii) Mass number of X = 17 + 20 = 37 

(iii) Atomic number of X = 17