Name the process which releases energy in the Sun and describe what happens in this process.

Here are the solutions to the questions:

Question 2:

• a) Name the process which releases energy in the Sun and describe what happens in this process.

  • Name: Nuclear Fusion
  • Description: In nuclear fusion, light atomic nuclei, primarily hydrogen nuclei (protons), combine under extreme temperature and pressure to form heavier nuclei, such as helium. During this process, a small amount of mass is converted into a large amount of energy, which is released as electromagnetic radiation (including sunlight).

• b) Explain why solar energy is called renewable energy.

  • Solar energy is considered renewable because its source, the Sun, is expected to continue producing energy for billions of years, far exceeding human timescales. The rate at which we use solar energy does not deplete its source.

• c) Select and explain three features of the solar panel that maximises the final temperature of the water.

  1. Black painted surfaces (copper pipes and metal backing sheet): Black surfaces are excellent absorbers of thermal radiation (sunlight). By painting the pipes and backing sheet black, they absorb a maximum amount of solar energy, converting it into heat to warm the water.
  2. Glass sheet: The glass sheet allows short-wavelength solar radiation to pass through and heat the black surfaces. However, it traps the longer-wavelength infrared radiation re-emitted by the hot surfaces, preventing heat loss by radiation (the greenhouse effect). It also reduces heat loss by convection from the hot pipes to the cooler surroundings.
  3. Insulating material: The insulating material placed behind the metal backing sheet reduces heat loss by conduction to the roof or the environment. This ensures that more of the absorbed heat is transferred efficiently to the water flowing through the copper pipes.