Smallest among these species is

• lithium

• lithium ion

• hydrogen

• helium

Chloride ion and potassium ion are isoelectronic. Then

• potassium ion is relatively bigger

• depends on the other cation and anion

• their size are same

• chloride ion is bigger than potassium ion

Which metal is used to make alloy steel for armour plates, safes and helmets?

• Al

• Mn

• Cr

• Pb

The element with atomic number 36 belongs to ........ block in the periodic table.

• p

• s

• f

• d

Among Na⁺, Na, Mg and Mg²⁺ the largest particle is

• Mg²⁺

• Mg

• Na

• Na⁺

136.

Mg²⁺ is isoelectronic with

• Cu²⁺

• Zn²⁺

• Na⁺

• Ca²⁺

The electronic configuration of Cr³⁺ is

• [Ar] 3d⁴ 4s²

• [Ar] 3d³ 4s⁰

• [Ar] 3d² 4s¹

• [Ar] 3d⁵ 4s¹

An ionic compound is expected to have tetrahedral structure if r+/r- lies in the range of

• 0.414 to 0.732

• 0.225 to 0.414

• 0.155 to 0.225

• 0.732 to 1

The correct order of ionisation energy of C, N, O, F is

• F < O < N < C

• F < N < C < O

• C < N < O < F

• C < O < N < F

The oxide of an element whose electronic configuration is 1s², 2s², 2p⁶, 3s¹ is

• neutral

• amphoteric

• basic

• acidic