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Question
The atomic number of calcium and argon are 20 and 18 respectively, but the mass number of both these elements is 40. What is the name given to such a pair of elements?
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Solution
A pair of elements in which the elements have a same mass number but different atomic numbers are called isobars. Hence `""_20^40"Ca"` and is `""_18^40"Ar"` are isobars.
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