Atomic size of potassium is bigger than atomic size of sodium.

Question

Give scientific reasons:

Atomic size of potassium is bigger than atomic size of sodium.

Answer 1

• The atomic size of an element depends on the number of electron orbits in the atom of that element. 
• The greater the number of orbits, the larger the size. 
• Atomic number of potassium (K) is 19. Hence, its electronic configuration is (2, 8, 8,1). While atomic number of sodium (Na) is 11. Hence its electronic configuration is (2, 8,1) 
• Number of orbits in potassium atom is 4, while that in sodium atom is 3. 
• Hence, atomic size of potassium is bigger than atomic size of sodium.