question_answer

             Study the data given below and answer the questions which follow:

Particles	Electrons	Protons	Neutrons
A B C D	2 10 8 8	3 9 8 9	4 8 8 10

(a) Write the mass number and atomic number of particles A, 5, C, D. (b) Which particles represent a pair of isotopes? Explain.  

Answer:

                       (i) Number of protons = 8 Number of electrons = 8 Number of neutrons =16-8 = 8       (ii) Valency 8 ? 6 = 2        (iii) (a)                       (b)