Consider the statements. I: Boron forms mainly covalent compounds. II: $AlCl X_{3}$ exists as the dimer $Al X_{2} Cl X_{6}$ in the vapour phase and in non-polar solvents. III: $Tl X^{+}$ is more stable than $Tl X^{3 +}$ . IV: Diamond is a good conductor of electricity. The number of correct statements is

AOne
BTwo
CThree
DFour

Answer: C

I (high ionisation enthalpy and small size), II (bridged dimer) and III (inert pair effect) are correct. IV is false because all four valence electrons of diamond carbon are localised in sigma bonds. So three statements are correct.

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Consider the statements. I: Boron forms mainly covalent compounds. II: AlClX3​ exists as the dimer AlX2​ClX6​ in the vapour phase and in non-polar solvents. III: TlX+ is more stable than TlX3+. IV: Diamond is a good conductor of electricity. The number of correct statements is

Answer: C

More questions on Trends in group 13 and group 14