Identify a metalloid from the following list of elements.

• Carbon

• Neon

• Sodium

• Tellurium

Identify the weakest oxidising agent among the following.

• Li⁺

• Na⁺

• Cd⁺

• I₂

Which of the following statement(s) is/are incorrect for pair of elements Zr-Hf?

• Both possess same number of valence electrons

• Both have identical sizes

• Both have almost identical radii

• Both of these belong to same period of periodic table

44.

Which element among the following does not form diatomic molecules?

• Argon

• Oxygen

• Nitrogen

• Bromine

Which of the following is covalent?

• NaCl

• KCl

• BeCl

• MgCl₂

Choose the wrong statement from the following 

• The 'silver' UK coins are made of Ag/ Ni alloy 

• TiO₂ is used in the pigment industry

• MnO₂ is used in the dry battery cells

• V₂O₅ catalyses the oxidation of SO₂ in the manufacture of sulphuric acid

The correct discending order of oxidising power of the following is

• ${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-} > {\mathrm{MnO}}_4^{-} > {\mathrm{VO}}_2^{+}$

• ${\mathrm{MnO}}_4^{-} > {\mathrm{Cr}}_2{\mathrm{O}}_7^{2-} > {\mathrm{VO}}_2^{+}$

• ${\mathrm{VO}}_2^{+} > {\mathrm{MnO}}_4^{-} > {\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$

• ${\mathrm{MnO}}_4^{-} > {\mathrm{VO}}_2^{+} > {\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$

The number of electrons that are involved in the reduction of permanganate to manganese (II) salt, manganate and manganese dioxide respectively are

• 5, 1, 3

• 5, 3, 1

• 2, 7, 1

• 5, 2, 3

The ionisation enthalpy of He⁺ ion is 19.60 10^-18 J atom^-1. The ionisation enthalpy of Li²⁺ ion will be

• 84.2 × 10^-18 J atom^-1

• 44.10 × 10^-18 J atom^-1

• 63.20 × 10^-18 J atom^-1

• 21.20 × 10^-18 J atom^-1

Among the elements B, Mg, Al and K the correct order of increasing metallic character is

• B < Al < Mg < K

• B < Mg < Al < K

• Mg < B < Al < K

• Mg < Al < B < K