Question

The following data represents the distribution of electrons, protons and

neutrons in atoms of four elements A, B, C, and D.

A B C D

Protons 19 17 17 18

Neutrons 21 18 20 22

Electrons 19 17 17 18

2

(a) What is the mass number of A?

(b) Write the electronic configuration of B.

(c) Which two elements form a pair of isotopes?

(d) Which two elements form a pair of isobars?​

Answer 1

Answer:

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