The structure of diborane (B₂H₆) contains

• four 2C-2e^- bonds and four 3C-2e^- bonds

• two 2C-2e^- bonds and two 3C-3e^- bonds

• two 2C-2e^- bonds and four 3C-2e^- bonds

• four 2C-2e^- bonds and two 3C-2e^- bonds

Dry ice is:

• solid SO₂

• Solid NH₃

• Solid O₂

• Solid CO₂

The elements commonly used for making transistors are :

• C and Si

• Ga and In

• P and As

• Si and Ge

Buckminster fullerene is :

• pure graphite

• C-60

• diamond

• C-90

White lead is

• PbCO₃PbO

• PbCO₃

• Pb(OH)₂.2PbCO₃

• PbSO₄.PbO

In silica (SiO₂), each silicon atom is bonded to

• two oxygen atoms

• four oxygen atoms

• one silicon and two oxygen atoms

• one silicon and four oxygen atoms

C-C bond length is maximum in

• diamond

• graphite

• naphthalene

• fullerone

Dry ice is

• Solid H₂O

• Solid CO₂

• Solid N₂O₄

• Solid NH₃

89.

When borax is heated strongly, it gives

• BaBO₂

• B₂O₃

• B₃N₃H₆

• Na₂B₄O₇

Sindhur, an oxide of lead, is an example of ............. oxide.

• basic

• super

• mixed

• amphoteric