Question

Which of the following statements are true?

Fusion reactions result in nuclei with higher Z.

To keep a nuclear power plant going, a chain reaction must be maintained.

Nuclear fusion produces no long-lived radioactive by-products.

The Sun is a nuclear fusion reactor.

I tried true, false, false, true and my teacher said that this was incorrect. Please help

Answer 1

1;2;;4; So I think your second one is incorrect. Consider fusion of two hydrogent to make Helium

Answer 2

just for clarification. 1, 2, and 4 are true

Answer 3

"Nuclear fusion produces no long-lived radioactive by-products. "

Perhaps it depends on wht you mean by 'long lived' and if only by-products from the actual fusion are considered. There are disposal considerations for radioactive waste from fusion.

For info on fusion see the JET web site.

I would have put

T,T,F,T

1 is somewhat vague. Assuming that 1 is referring to a fission plant that is producing energy by fission. A fission plant will still produce heat/energy from decay heat, i.e. with out maintaining a chain reaction. This is a problem with the Japanese reactors, which are producing lots of decay heat.