Calcium (atomic number 20) and argon (atomic number 18) have a mass number of 40. What are they known as?
Isotones
Isochores
Isobars
Isotopes
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC CDS-1 – 2017
– Isotones are atoms of different elements (different atomic numbers) with the same number of neutrons. For Calcium-40, neutrons = 40-20 = 20. For Argon-40, neutrons = 40-18 = 22. They are not isotones.
– Isochores relate to constant volume processes in thermodynamics, not atomic structure.