Correct Answer: B. The scarcity of productive resources relative to society's unlimited wants

Explanation

The fundamental problem of Economics is Scarcity. Scarcity explains the basic economic problem that the world has limited or scarce resources to meet seemingly unlimited wants, and this reality forces people to make decisions about how to allocate resources in the most efficient way.

Correct Answer: A. Pituitary gland

Correct Answer: D. light

Explanation

(a) Explanation of chemical weathering of rocks:

Chemical weathering is the decomposition of rocks by chemical agents formed through the reaction of water with atmospheric gases such as air (oxygen and carbon dioxide) As some minerals in the rocks are dissolved and others change into new chemical products therefore disintegration of rocks occurs.

(b)Discussion of chemical weathering of rocks (Any four)

Hydration

Occurs when water combines with or binds to some minerals Intact water may bind to silicates, oxides of iron

Hydrated compounds are soft and easily fragmented It does not usually affect the chemical composition of the hydrated product

Example of hydration reaction are

Fe203 + 3H20 → . Fe203.3H20

Haematite Limonite/Hydrated Haematite (Yellow)

(Red)

OR

CaSO4 + 2H20 → CaSO4 .2H20

(Calcium Sulphate) (Gypsum)

OR CuS04 + 5H20 → CuS04. 5H20

(Anhydrous Copper Sulphate)Carbonation (Hydrated Copper II sulphate )/Blue stone/

Carbonation

This is brought about by the combination of carbonate (C02-3) or bicarbonte (HCO-3) ions with rock minerals

The carbon dioxide released to the atmosphere from various sources combines with water/rainwater to form carbonic acid

C02 + H20 →← H2C03

The carbonic acid attacks the minerals and C02 in the rock.

In limestone or marbles the calcite present is dissolved.

CaCO₃ + H₂CO₃ → Ca(HCO₃)₂ →

Oxidation/Reduction

Atmospheric oxygen and free oxygen in rain water carry out this reaction

Minerals containing iron (Ferrous form), manganese and sulphur are the ones most frequently affected by this reaction

When they are exposed to air and water, the ferrous ion is oxidized to the ferric Fe2 + state.

The change in valency from Fe ++ to Fe + destabilizes the molecule and leads to disintegration

4Fe C03 + 02→ 2Fe203 + 4C02

Iron (II) Oxygen Iron Oxide Carbon dioxide

carbonate

Hydrolysis

A decomposition reaction in which silicate minerals are broken down Water molecule is split into H+ and OR ions

H₂0 + H⁺ → HO^-

The H+ replaces the cation from the mineral structure while the mineral is released for plant uptake

Example:

CaSi03 + 2H20 → H2Si03 + Ca(OH)2

Calcium silicate water

Correct Answer: C. 1 4 5 3 2

Correct Answer: D) life lived after salvation

Explanation

In the Epistles, the phrase new life symbolizes something important. This question is asking you to choose the correct option that best describes what the phrase means. The options are A, B, C, and D. Option A is life under grace, Option B is sinful life, Option C is life as infant, and Option D is life lived after salvation. The correct answer is Option D.

New life refers to the life that a person lives after they have accepted salvation through Jesus Christ. This new life is different from the old life they used to live before they became Christians. It is a life that is lived in accordance with God's will and guided by the Holy Spirit. This new life is characterized by a desire to please God, to live righteously, and to love others.

Option A, life under grace, refers to the fact that Christians are saved by grace through faith in Jesus Christ. Option B, sinful life, is not correct because the new life that Christians are called to live is a life free from sin. Option C, life as infant, is not correct because though Christians are referred to as spiritual infants when they first become believers, the phrase new life does not symbolize this.

In summary, the phrase new life as used in the Epistles symbolizes the life lived by a person after they have accepted salvation through Jesus Christ. This life is characterized by a desire to please God, to live righteously, and to love others. Option D is the correct answer to this question.

Correct Answer: A) 100KJ

Correct Answer: C. caused by the environment

Explanation

(b) The mechanism of hearing in mammals begins with sound waves first reaching the pinna and passing along the auditory meatus to the ear drum. This causes vibration which passes along the ossicles. The ossides amplify the vibrations which are transmitted to the inner ear via the oval window. This sets the endolymph in the inner ear (cochlea) to vibrate. Impulses are then set up by the hair cells of the cochlea and transmitted via the auditory nerve to the brain for interpretation.

(c) Care for the ear:

(i) Clean ear regularly with cotton wool or swab to remove dust and wax. Also avoid puncturing the ear drum by avoiding sharp objects and loud noise.

(ii) Always see the doctor in case there is any ear trouble.

Correct Answer: C. daughter