P7.8 - Nuclear Fusion (Finished)

Question 1

What is nuclear fusion

Answer 1

Nuclear fusion is the process of forcing two nuclei close enough so that they form a single larger nucleus

Question 2

What happens in nuclear fusion?

Answer 2

In nuclear fusion two light nuclei collide at high speed and join to create a larger heavier nucleus and release energy in the form of radiation

Question 3

Why does nuclear fusion release energy when nuclei collide?

Answer 3

The heavier nucleus produced by fusion does not have as mass as the two separate nuclei had so some of the mass of the lighter ones is converted to energy released as radiation

Question 4

Up to what point can fusion occur?

Answer 4

Fusion can occur only if the relative mass of the nucleus produced is less than or equal to 55. Otherwise energy must be supplied

Question 5

Why would fusion be so useful?

Answer 5

• The fuel of fusion reactors is easily available; heavy hydrogen is naturally found in seawater
• The product is harmless helium
• The energy released can be used to generate electricity

Question 6

What is the problem of fusion on earth?

Answer 6

The plasma of light nuclei has to be heated to really high temperatures and pressures to overcome the repelling force of the two nuclei coming together

Question 7

What is done in a fusion reactor to keep plasma hot?

Answer 7

• Plasma is heated by passing a very big electrical current through it
• The plasma is contained with a magnetic field do it doesn’t touch the reactor walls (it would cool down)