Question

5. Symbols (not real) of some atoms are given.
17. 40. 16. 40
P Q P R
8. 18. 8. 20

a) Find the atomic number and mass number of these
elements
b) Which among these are isotopic pairs?
c) Draw the Bohr model of atom Q.

Answer 1

Explanation:

Atomic mass is always greater than atomic number for any atom.

Here I am going to represent the atom in X(A,Z) where X, A, and Z will represent the atom, atomic mass and atomic number respectively.

(a) P(17,8)

Q(40,18)

P(16,8)

R(40,20)

(b) Atoms having same atomic number are Isotopes

P(17, 8) and P(16, 8) will be the isotopic pairs.

(c) Q

${18}^{Q} \: \: \: \: \: 1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6}$