Mention three benefits that Ghana could derive from nuclear energy.

Here are the answers to questions 3 and 4:

3. (a) (i) Mention three benefits that Ghana could derive from nuclear energy.

• Reliable and clean electricity generation to meet growing energy demands.
• Development of medical isotopes for diagnosis and treatment of diseases.
• Opportunities for scientific research and technological advancement in various fields.

3. a) (ii) List two types of nuclear radiation.

• Alpha ($\alpha$) radiation
• Beta ($\beta$) radiation
• Gamma ($\gamma$) radiation

3. (b) State the scientific principle involved in each of the following local industries:

• (i) kenkey production: Fermentation (by microorganisms).
• (ii) soap production: Saponification (hydrolysis of fats/oils with an alkali).
• (iii) salt production: Evaporation and Crystallization.
• (iv) vegetable oil production: Extraction (e.g., pressing or solvent extraction).
• (v) gari processing: Fermentation and Dewatering/Drying.

3. (c) (i) List two micronutrients in a soil.

• Boron (B)
• Zinc (Zn)
• Manganese (Mn)
• Iron (Fe)

3. (c) (ii) Differentiate between broadcasting and side dressing methods of fertilizer application.

• Broadcasting involves scattering fertilizer uniformly over the entire soil surface before or after planting.
• Side dressing involves applying fertilizer in bands along the sides of plant rows after the crops have started growing.

3. (d) (i) Differentiate between conductors and semi-conductors.

• Conductors are materials that allow electric current to flow through them easily due to a large number of free electrons.
• Semiconductors are materials with electrical conductivity between that of a conductor and an insulator, whose conductivity can be controlled by doping or temperature.

3. (d) (ii) Name two appliances in the home which use semi-conductors.

• Televisions (TVs)
• Computers
• Smartphones
• LED light bulbs

4. (a) (i) State three conditions to be considered when selecting viable seeds for planting.

• The seeds should be mature and fully developed.
• They should be free from pests and diseases.
• They should have a high germination percentage.
• They should be uniform in size and shape.

4. (a) (ii) State two characteristics of good seeds.

• High viability (ability to germinate and grow).
• Free from physical damage or cracks.
• Good genetic purity (true to type).
• Resistant to common diseases and pests.

4. (b) (i) State Ohm's law.
Ohm's law states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points, and inversely proportional to the resistance between them, provided the temperature and other physical conditions remain constant.

$$V = IR$$

4. (b) (ii) A resistor has a resistance of $12.5 \, \Omega$. If a current of $10 \, \text{A}$ passes through the resistor, calculate the potential difference across the resistor.