The number of electrons in an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of the element?
  1. 31X15
  2. 31X16
  3. 16X15
  4. 15X16

AcademicChemistryNCERTClass 9

Correct Answer: (a)  31X15  

Explanation: In an atom, the number of electrons is equal to the number of protons, which in turn is equal to the atomic number of the element. Also, the sum of the number of protons and neutrons represents the mass number of the element.

Updated on 10-Oct-2022 13:32:55