c) i. State the type of bond that exists in:

Mass, $m = 3 \text{ kg}$
Height, $h = 15 \text{ m}$
Acceleration due to gravity, $g = 10 \text{ m/s}^2$

The potential energy of the body is $\boxed{\text{450 J}}$.

d) ii. Give two examples of first class lever.

1. Seesaw
2. Crowbar (when used to pry something)

5. a) i. Explain briefly the term dispersion of light.
Dispersion of light is the phenomenon where white light separates into its constituent colors (forming a spectrum) when it passes through a transparent medium, such as a prism. This occurs because different wavelengths (colors) of light travel at slightly different speeds in the medium, causing them to refract at different angles.

5. a) ii. Describe briefly how rainbow is formed.
A rainbow is formed when sunlight interacts with water droplets in the atmosphere. Each water droplet acts like a tiny prism, dispersing the white sunlight into its spectrum of colors. The light then undergoes total internal reflection inside the droplet and is refracted again as it exits, sending the separated colors back towards the observer.

5. b) i. Mention three properties of covalent bond.

1. Low melting and boiling points: Covalent compounds generally have weaker intermolecular forces, requiring less energy to overcome.
2. Poor electrical conductivity: They typically do not have free ions or mobile electrons to conduct electricity.
3. Exist as gases, liquids, or soft solids: Due to weak intermolecular forces, many covalent compounds are found in these states at room temperature.

5. b) ii. State the difference between an electrically neutral atom and an ion.
An electrically neutral atom has an equal number of protons (positive charges) and electrons (negative charges), resulting in no net electrical charge. An ion is an atom or molecule that has gained or lost one or more electrons, giving it a net positive (cation) or negative (anion) electrical charge.

5. c) i. What are micro-elements in plant nutrition?
Micro-elements (or micronutrients) are essential plant nutrients that are required by plants in very small quantities for their growth, metabolism, and overall development. Despite their small required amounts, they are crucial for various biochemical processes and enzyme activities.

5. c) ii. Give three examples of micro-elements.

1. Iron (Fe)
2. Manganese (Mn)
3. Zinc (Zn)

5. d) i. State two differences between the alimentary canal of a domestic fowl and the alimentary canal of a human.

1. Presence of Crop and Gizzard: A domestic fowl possesses a crop for food storage and softening, and a muscular gizzard for grinding food (as they lack teeth). Humans do not have a crop or gizzard; mechanical digestion is performed by teeth and the churning action of the stomach.
2. Cloaca: Fowls have a cloaca, a single posterior opening for digestive, urinary, and reproductive tracts. Humans have separate openings for these functions (anus for feces, urethra for urine, and distinct reproductive organs).

5. d) ii. List two disorders of the digestive system of humans.

1. Gastritis (inflammation of the stomach lining)
2. Peptic Ulcer (sores in the lining of the stomach or small intestine)