question_answer 65)

  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? A pair of elements having same mass number but different atomic number is called isobars.

Answer:

  Mass number of calcium 40 i.e., Mass number of argon 40 i.e., A pair of elements having same mass number but different atomic number is called isobars.