Question

State the position of the following in the Periodic Table: [4 MARKS]
(a) Alkali metals
(b) Alkaline earth metals
(c) Iron and zinc
(d) Aluminium

Answer 1

Each Part: 1 Mark

(a) Alkali metals : Elements of group I are called alkali metals. They have 1 electron in their outermost orbit and show a valency of one. Alkali metals are lithum (Li), sodium (Na), potassium (K), rubidium (Rb), caseium (Cs) and francium (Fr).

(b) Alkaline earth metals: Elements such as beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Br) and radium (Ra).
All of them have two electrons in their outermost orbit and show a valency of two. They are placed in group 2 of the periodic table.

(c) Iron and zinc: Iron (Z = 26) : 2, 8, 14, 2
Period : 4 (number of orbits or shells)
Group : 8
Zinc (Z = 30) : 2, 8, 18, 2
Period : 4 (number of orbits or shells)
Group :12

(d) Aluminium: Al (Z = 18) : 2, 8, 3
Period = 3 (number of shells or orbits)
Group = 13