Chemistry 2005 Jamb Examination

Copper is the most suitable metal for lightning conductors because it is a good conductor of electricity, highly ductile, and resistant to corrosion. It can easily channel the high voltage current from lightning into the ground.

Although silver is a better conductor, it is too expensive. Iron and aluminium are less effective because of corrosion and lower conductivity compared to copper.

Arrhenius law relates reaction rate to temperature and activation energy. The correct curve should show the exponential increase in rate with temperature, which is typically represented by curve X in this type of graph.

The other curves represent unrelated patterns of change. Curve X best fits the theoretical prediction of Arrhenius behaviour.

Oxygen is the most abundant element in the earth’s crust. It occurs mainly in the form of oxides, silicates, and carbonates, making up almost half the mass of the crust.

Nitrogen and hydrogen are abundant in the atmosphere, not the crust, while fluorine occurs in much smaller amounts.

Metalloids are elements that exhibit properties of both metals and non-metals. For this reason, they are also called semi-metals.

They often act as semiconductors and play a key role in the electronics industry. Examples include silicon and arsenic.

Froth flotation is an industrial process used mainly for the concentration of sulphide ores. The process exploits differences in surface properties between the valuable mineral particles and waste particles.

Oxide and nitride ores are concentrated using other methods such as magnetic separation or gravity separation, not flotation.

Copper is the most suitable metal for lightning conductors because it is a good conductor of electricity, highly ductile, and resistant to corrosion. It can easily channel the high voltage current from lightning into the ground.

Although silver is a better conductor, it is too expensive. Iron and aluminium are less effective because of corrosion and lower conductivity compared to copper.

Arrhenius law relates reaction rate to temperature and activation energy. The correct curve should show the exponential increase in rate with temperature, which is typically represented by curve X in this type of graph.

The other curves represent unrelated patterns of change. Curve X best fits the theoretical prediction of Arrhenius behaviour.

Oxygen is the most abundant element in the earth’s crust. It occurs mainly in the form of oxides, silicates, and carbonates, making up almost half the mass of the crust.

Nitrogen and hydrogen are abundant in the atmosphere, not the crust, while fluorine occurs in much smaller amounts.

Metalloids are elements that exhibit properties of both metals and non-metals. For this reason, they are also called semi-metals.

They often act as semiconductors and play a key role in the electronics industry. Examples include silicon and arsenic.

Froth flotation is an industrial process used mainly for the concentration of sulphide ores. The process exploits differences in surface properties between the valuable mineral particles and waste particles.

Oxide and nitride ores are concentrated using other methods such as magnetic separation or gravity separation, not flotation.