posted by Grace .
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.
yes; no; no; yes, sort of;
let me amplify on the chain reaction. A power reactor controls the reaction. Nuclear decay produces energy (heat) that the steam generators need. So to get more energy, the reactors move contol rods such that fission causing neutrons are allowed to cause more atoms to split. If less energy is needed,the controlrods absorb the neutrons, slowing down the decay rate and heat production. It is this control of the rate of fission that allows the nuclear material to produce the heat needed. One has to maintain this control.