Give reasons

(a) Physical properties of isotopes are different.

(b) Argon does not react.

(c) Actual atomic mass is greater than mass number.

(d) ³⁵₁₇Cl and ³⁷₁₇Cl do not differ in their chemical reactions.

(a) Physical properties depend on the atomic mass (mass number) and isotopes have different mass numbers due to different number of neutrons hence they differ in their physical properties.

(b) Argon [2, 8, 8] does not react or do not combine either with other atoms or among themselves to form molecules, since their octet is already complete, hence, they are in a stable state and their combining capacity is zero.

(c) Actual atomic mass is greater than the mass number because the mass number is a whole number approximation of atomic mass unit. Actual atomic mass is fractional as it is the weighted average of all the naturally occurring isotopes of that element.

(d) Chemical properties are determined by the electronic configuration of an atom and electronic configuration of both isotopes of chlorine is same, i.e., electronic configuration of ³⁵₁₇Cl is [2,8,7] and electronic configuration of ³⁷₁₇Cl is [2,8,7], hence they both have same chemical properties.