Question

Atoms of different elements with the same number of neutrons are called:

• A. Isotopes
• B. Isomers
• C. Isobars
• D. Isotones

Hint:

Isotones have the same number of neutrons, which gives them similar nuclear properties, but different chemical properties.

Answer 1

The Correct Option is D

• Option 1: Isotopes - This is incorrect. Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons, not atoms of different elements with the same number of neutrons.
• Option 2: Isomers - This is incorrect. Isomers are molecules that have the same molecular formula but different structural arrangements, not atoms with the same number of neutrons.
• Option 3: Isobars - This is incorrect. Isobars are atoms of different elements that have the same mass number (atomic mass), not the same number of neutrons.
• Option 4: Isotones - This is the correct answer. Isotones are atoms of different elements that have the same number of neutrons, but different numbers of protons and thus belong to different elements.

Explanation: 

Atoms of different elements with the same number of neutrons are called isotones. Although they have the same number of neutrons, they have different atomic numbers (protons), meaning they belong to different elements.

Answer 2

Carbon-14 and Nitrogen-15 make a good real pair to test this definition against, since both are commonly cited isotones.

1. Isotopes: Carbon, with 6 protons, and Nitrogen, with 7 protons, are different elements, so they cannot be isotopes of one another, since isotopes must share the same element.
2. Isomers: This describes molecules with one formula but different structures. Carbon-14 and Nitrogen-15 are single atoms, not molecules, so this cannot apply.
3. Isobars: Carbon-14 has a mass number of 14, while Nitrogen-15 has a mass number of 15. Since these mass numbers are different, this pair does not qualify as isobars either.
4. Isotones: Carbon-14 has 6 protons and 8 neutrons (6 + 8 = 14), and Nitrogen-15 has 7 protons and 8 neutrons (7 + 8 = 15). Both atoms carry 8 neutrons even though they are different elements with different mass numbers, and that shared neutron count is exactly what defines isotones.

Carbon-14 and Nitrogen-15 belong to different elements and have different mass numbers, but both hold 8 neutrons, which is the isotone relationship.

So the correct answer is Isotones.