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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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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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Chapter 4: Structure of the Atom - Short Answer Questions [Page 31]

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NCERT Exemplar Science Exemplar [English] Class 9
Chapter 4 Structure of the Atom
Short Answer Questions | Q 31. | Page 31

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