(a)i) Definition of isotopes;
Atoms of the same element that have the same number of protons but different number of neutron.
OR
Same atomic number but different mass number

(ii) (\(\alpha\)) Uses of Radioactive Tracers in Medicine;
- monitoring the function of the thyroid gland/other organs.
- detection of blood clots in the brain.
- diagnosis and treatment of disease
- sterilization of medical equipment
(\(\beta\)) Uses of tracers in industry
Detection of;
- leakages in underground pipes
- wear and tear of moving parts of machinery:
- environmental pollution
(\(\gamma\) ) Uses of tracers in agriculture
- determination of plants absorption of mineral elements;
- study of the mechanism of photosynthesis;
- seed preservation;
- sterilization of insects;
- food preservation.

(b) Calculation of the minimum frequency of radiation

OR
f\(_o\) = f - \(\frac{E}{b}\)
= 5.4 x 10\(\frac{1}{2}\) - \(\frac{1.2 \times 10^{-19}}{6.6 \times 10^{34}}\)
= 3.6 x 10\(^4\)Hz

(c) Features of electromagnetic waves
- Transverse waves,
- Travel with the speed of light in vacuum;
- Undergo refraction/reflection/diffraction/polarization/interference
- Travel through vacuum.

(d)(i) Components of the nuclear reactor;
- uranium fuel
- graphite moderator;
- (boron) control rod
- coolant;
- heat exchanger;
- shield
(ii) Functions of the component of the nuclear reactor;
- uranium rods
- serves as fuel;
- graphite moderator
- control neutron speed; (boron) control rod
- Controls neutron population; coolant
- reduces the excessive heat produced in the reaction; heat exchanger
- converts the heat energy produced to other forms; shield
- to protect operator and surroundings against extraneous radiation