Question

The following table represents the first 20 elements of the Periodic table (the symbol and the electronic configuration for the outermost shell for each of the 20 elements are given).

IA							0
H 1	IIA	IIIA	IVA	VA	VIA	VIIA	He 2
Li 2,1	Be 2,2	B 2, 3	C 2,4	N 2,5	O 2,6	F 2,7	Ne 2,8
Na 2,8,1	Mg 2,8, 2	Al 2,8,3	Si 2,8,4	P 2,8,5	S 2,8,6	Cl 2,8,7	Ar 2,8,8
K 2,8,8, 1	Ca 2,8, 8, 2

Group IIIA elements have _____ electrons in their outermost shell.

Answer 1

• Valence electrons of an element are defined as the number of electrons present in the outermost shell of that element.
• Valence electrons in any element in Group 1, 2, and 13 to 18 can be predicted by its group number. Example, elements in Group 1 or Group IA have 1 valence electron.
• According to the electronic configuration of Group IIIA elements (Boron (B) and Aluminum (Al)), the electrons present in the outermost or valence shell are 3.
• Thus, Group IIIA elements have 3 electrons in their outermost shell.