Pakistan MCQs

Axons conduct action potentials to target cells.
Some are insulated by myelin.

Every carbon is tetrahedrally bonded to four others.
The extended network resists deformation.

Axons conduct action potentials to target cells.
Some are insulated by myelin.

Amphoteric oxides can behave as acidic or basic substances.
Aluminum oxide and zinc oxide are examples.

Axons conduct action potentials to target cells.
Some are insulated by myelin.

SO3 is a nonmetal oxide and forms sulfuric acid with water.
Metal oxides listed are predominantly basic.

For first order, rate=k[A].
Rate=0.20×0.50=0.10 M/s.

Sodium oxide reacts with water to form sodium hydroxide.
It is a strongly basic metal oxide.

The rate depends on the square of concentration.
Doubling gives 2²=4 times the rate.

Transition-metal chemistry arises from partially filled d orbitals.
Common features include variable oxidation states and colored ions.

Four oxygens contribute -8 total.
Sulfur must be +6 so the ion total is -2.

Ligands split d-orbital energies.
Absorption of selected visible wavelengths gives the observed complementary color.