Question

Given the element helium has mass number 4 and 2 electrons.Find the atomic number, mass number, number of protons, number of neutrons and electronic configuration of the same.

Answer 1

• Atomic number is the number of protons in an atom.
• In a neutral atom, the number of electrons and protons will be same.
• Number of electrons is given as 2, hence the number of protons and atomic number will be also 2.
• Mass number is the sum of number of protons and neutrons in an atom.
• Mass number is given as 4.Thus number of neutrons=mass number-number of protons=(4-2)=2.
• Electronic configuration is the arrangement of electrons in energy levels around an atomic nucleus i.e.,2,2
• Since the number of electrons is 2, electronic configuration:2.