For which element the inertness of the electron pair will not be observed? 

• Sn

• Fe

• Pb

• In

Composition of azurite mineral is

• CuCO₃.CuO

• Cu(HCO₃)₂.Cu(OH)₂

• 2CuCO₃.Cu(OH)₂

• CuCO₃.2Cu(OH)₂

When H₂S gas is passed in a metal sulphate solution in presence of NH₄OH, a white precipitate is produced. The metal is identified as:

• Zn

• Fe

• Pb

• Hg

Which of the following is philosopher's wool ?

• ZnO

• HgO

• Ag₂O

• CuO

₈₄Rn²¹⁹ is a member of actinium series. The other member of this series is-

• ₈₉Ac²²⁵

• ₉₀Th²³²

• ₁₅P³⁵

• ₉₂U²³⁵

Which one is malachite from the following?

• Cu(OH)₂

• Fe₃O₄

• CuCO₃.Cu(OH)₂

• CuFeS₂