Question 17 of 42beginner🔧 ApplyShort Answer3 marks
Identify the number of electrons in the outermost shell of the following elements:
(i)
12/6 C
Answer
4
(ii)
19/9 F
Answer
7
(iii)
28/14 Si
Answer
4
Explanation
To find the number of electrons in the outermost shell, we distribute the total electrons (equal to the atomic number) using Bohr and Bury rules. The K-shell holds a maximum of 2 electrons, and the L-shell holds a maximum of 8 electrons. Electrons fill stepwise from the K-shell outwards.
(i) For ⁶₁₂C: Atomic number is 6. K-shell has 2 electrons, L-shell has 4. The outermost shell has 4 electrons.
(ii) For ⁹₁₉F: Atomic number is 9. K-shell has 2 electrons, L-shell has 7. The outermost shell has 7 electrons.
(iii) For ¹⁴₂₈Si: Atomic number is 14. K-shell has 2, L-shell has 8, M-shell has 4. The outermost shell has 4 electrons.