Question

Given the element, sodium has mass number 23 and atomic number 11. Find the number of protons, number of neutrons, number of electrons and electronic configuration of the same.

Answer 1

• The atomic number is the number of protons in an atom.
• Since the atomic number is given as 11, the number of protons will be also 11.
• In a neutral atom, the number of protons and electrons will be the same. Thus the number of electrons is also 11.
• The electronic configuration is the arrangement of electrons in energy levels around an atomic nucleus.
• Thus electronic configuration: 2,8,1.
• The mass number is the sum of the number of protons and neutrons in an atom.
• The mass number is given as 23.
• Hence number of neutrons=mass number-number of protons=(23-11)=12.