Practice Pakistan questions with answers and explanations.
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The side length is √144 = 12 cm.
The perimeter is 4 × 12 = 48 cm.
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Electron groups arrange to minimize repulsion.
Lone pairs and bonding regions determine molecular geometry.
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Triangle area is one-half × base × height.
Thus, 1/2 × 10 × 6 = 30 cm².
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Two electron groups arrange 180 degrees apart.
This minimizes repulsion.
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Parallelogram area is base times perpendicular height.
Thus, 15 × 8 = 120 cm².
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Three electron groups arrange about 120 degrees apart.
They lie in one plane.
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Four electron groups point toward tetrahedral corners.
The ideal bond angle is about 109.5 degrees.
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Carbon in methane has four bonding pairs and no lone pairs.
The molecular geometry is tetrahedral.
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Nitrogen has three bonds and one lone pair.
The lone pair changes the molecular shape from tetrahedral electron geometry.
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Oxygen has two bonding pairs and two lone pairs.
Lone-pair repulsion produces a bent molecule.
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Carbon has two electron domains from the two double bonds.
They arrange 180 degrees apart.
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Boron has three bonding regions and no lone pairs.
The molecule is planar with approximately 120-degree angles.
