Which statement about fusion reactors is true? a enriched uranium isotopes are used as fuel in fusion reactors. b fuel for fusion reactors can be extracted form ocean water. c fusion reactors are now replacing fission reactors. d fusion reactors produce radioactive waste as spent fuel .

b Fuel for fusion reactors can be extracted from ocean water.  

Explanation:

The fuel is deuterium, which makes up 0.02% of the hydrogen atoms in water. The oceans contain more than a billion cubic kilometres of water, so that's a lot of deuterium.

a is wrong. The fuel for fusion reactors is deuterium.

c is wrong.  There is much research, but there are no large-scale fusion reactors in operation.

d is wrong. Fusion reactors do not produce radioactive waste as spent fuel. Most of the radioactive waste would be the reactor core itself.

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

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tony (lordcaos066)

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.