The liquefied metal expanding on solidification is

• Ga

• Al

• Zn

• Cu.

The compound insoluble in water is

• mercurous nitrate

• mercuric nitrate

• mercurous chloride

• mercurous perchlorate.

Assertion : Barium is not required for normal biological function in human.

Reason : Barium does not show variable oxidation state.

• If both assertion and reason are true and the reason is the correct explanation of the assertion.

• If both assertion and reason are true and the reason is not the correct explanation of the assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

The atomic number of cerium (Ce) is 58. The correct electronic configuration of Ce³⁺ ion is.

• [Xe] 4f¹

• [Kr] 4f¹

• [Xe] 4f¹³

• [Kr] 4d¹

The decreasing order of basic character of K₂O, BaO, CaO and MgO is

• K₂O > BaO > CaO > MgO

• K₂O > CaO > BaO > MgO

• MgO > BaO > CaO > K₂O

• MgO > CaO > BaO > K₂O

496.

Which of the following is correct?

• Radius of Ca²⁺ < Cl^- < S^2-

• Radius of Cl^- < S^2- < Ca²⁺

• Radius of Cl^- = S^2- = Ca²⁺

• Radius of S^2- < Cl^- < Ca²⁺

Metal ion responsible for the Minimata disease is

• CO²⁺

• Hg²⁺

• Cu²⁺ 

• Zn²⁺

If the first ionization energy of H atom is 13.6 eV, then the second ionization energy of He atom is:

• 27.2 eV

• 40.8 eV

• 54.4 eV

• 108.8 eV

Which one of the following has the lowest ionisation energy?

• 1s² , 2s² , 2p⁶

• 1s² , 2s² , 2p⁶ , 3s¹

• 1s² , 2s² , 2p⁵

• 1s² , 2s² , 2p³

Which of the following statements about the interstitial compounds is incorrect?

• They retain metallic conductivity

• They are chemically reactive

• They are much harder than the pure metal

• They have higher melting points than the pure metal