What are the benefits of nuclear energy for Ghana, types of nuclear radiation, scientific principles in local industries, micronutrients in soil, and fertilizer application methods?

Here are the answers to the questions:

3. (a) (i) Three benefits that Ghana could derive from nuclear energy are:

• Reliable and large-scale electricity generation to meet growing energy demands.
• Reduced reliance on fossil fuels, leading to lower greenhouse gas emissions.
• Creation of high-skilled jobs in construction, operation, and maintenance of nuclear facilities.

3. (a) (ii) Two types of nuclear radiation are:

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

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

• (i) kenkey production: Fermentation (involving microorganisms converting carbohydrates to acids and alcohol).
• (ii) soap production: Saponification (hydrolysis of fats/oils with an alkali to produce soap and glycerol).
• (iii) salt production: Evaporation (separation of salt from water by heating or solar energy).
• (iv) vegetable oil production: Extraction (mechanical pressing or solvent extraction to separate oil from plant material).
• (v) gari processing: Fermentation (of cassava pulp to break down starches and remove cyanide), followed by dewatering and toasting/garification.

3. (c) (i) Two micronutrients in a soil are:

• Iron (Fe)
• Zinc (Zn)

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

• Broadcasting involves spreading fertilizer uniformly over the entire soil surface before or after planting.
• Side dressing involves applying fertilizer in bands along the sides of crop rows after the plants have emerged.

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

• Conductors are materials that allow electric current to flow easily through them due to a large number of free electrons (e.g., metals).
• Semi-conductors are materials with electrical conductivity between that of a conductor and an insulator, whose conductivity can be controlled by doping or temperature (e.g., silicon, germanium).

3. (d) (ii) Two appliances in the home which use semi-conductors are:

• Television
• Computer (or smartphone)

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

• Maturity: Seeds should be fully mature.
• Freedom from pests and diseases: Seeds should be healthy and undamaged.
• High germination rate: Seeds should be capable of sprouting successfully.

4. (a) (ii) Two characteristics of good seeds are:

• They are uniform in size and shape.
• They are free from foreign matter (e.g., dirt, weed seeds).

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, provided the temperature and other physical conditions remain constant. Mathematically, $V = IR$.

4. (b) (ii) Calculate the potential difference across the resistor.