ICSE Class 10 Answered
Dear Student,
(a) Carbon, Fluorine, Beryllium (decreasing order of atomic size) - Atomic size decreases from left to right across the period.
Hence, the decreasing order of atomic size would be:
Berylium (Grp 2, period 2) > Carbon (Grp. 4, period 14) > Fluorine (Grp. 17, period 2)
(b) Sulphuric acid, Phosphoric acid, Acetic acid (increasing order of number of replaceable H atoms per molecule)
Sulphuric acid (H2SO4) - 2
Phosphoric acid (H3PO4) - 3
Acetic Acid (CH3COOH) - 1
(c) Potassium, Lithium, Sodium (increasing order of ionization potential)
Ionisation potential decreases down the group.
Hence, the increasing order of ionisation potential would be:
Potassium ( grp 1, period 4) < Sodium (grp 1, period 3) < Lithium (grp 1, period 2)