Answer:
Cell Membrane
The thin, flexible outer covering of a cell. It controls what enters and leaves a cell.
Explanation:
453 divided by 224
density is roughly 2.02 g per ml
as a ml is 1 cm3 density is 2.02 grams per centimeter cubed
Answer:
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.
Answer: Endothermic reaction.
Explanation: A chemical reaction in which energy is absorbed from the surrounding environment.
Answer:
so the earth has an atmosphere, which holds in all the oxygen, it has gravity, and it has the green house effect, causing the earth's warmth to stay in it's atmosphere
