Question

The triad of nuclei that is isotonic is: a)6C14 ,7N14, 9F19 b)6C12, 7N14, 9F19 c)6C14 ,7N15, 9F17 d)6C14 ,7N14, 9F17

Answer 1

Answer: The correct answer is Option c.

Explanation:

Isotonic species are defined as the species which has same number of neutrons.

To calculate number of neutrons, we use the formula:

Number of neutrons = Mass number - Atomic number     ...(1)

For the given options:

Option a: $_6^{14}\textrm{C},_7^{14}\textrm{N}\text{ and }_9^{19}\textrm{F}$

Number of neutron in Carbon = 14 - 6 = 8

Number of neutrons in Nitrogen = 14 - 7 = 7

Number of neutrons in Nitrogen = 19 - 9 = 10

Thus, these are not isotonic species.

Option b: $_6^{12}\textrm{C},_7^{14}\textrm{N}\text{ and }_9^{19}\textrm{F}$

Number of neutron in Carbon = 12 - 6 = 6

Number of neutrons in Nitrogen = 14 - 7 = 7

Number of neutrons in Nitrogen = 19 - 9 = 10

Thus, these are not isotonic species

Option c: $_6^{14}\textrm{C},_7^{15}\textrm{N}\text{ and }_9^{17}\textrm{F}$

Number of neutron in Carbon = 14 - 6 = 8

Number of neutrons in Nitrogen = 15 - 7 = 8

Number of neutrons in Nitrogen = 17 - 9 = 8

Thus, these are considered as isotonic species.

Option d: $_6^{14}\textrm{C},_7^{14}\textrm{N}\text{ and }_9^{17}\textrm{F}$

Number of neutron in Carbon = 14 - 6 = 8

Number of neutrons in Nitrogen = 14 - 7 = 7

Number of neutrons in Nitrogen = 17 - 9 = 8

Thus, these are not isotonic species.

Hence, the correct answer is Option c.