“Star cluster” is a generic way for astronomers to refer to a group of stars that formed from the same material and are gravitationally bound for at least some period of time. There are two major types of star clusters — globular clusters and open clusters — and they are actually quite different.
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:
The correct formula for tetraphosphorous octaoxide is P₂O₅
Answer:
Single Replacement Reaction
Explanation:
simply because only 1 element switched places.
Answer:
0.375 grams are needed to make 25 mL solution.
Explanation:
Mass of 
cuprous nitrate required to make 1 l of solution = 15 g.
1 L = 1000 mL
Mass of cuprous nitrate required to make 1000 mL of solution = 15 g
Mass of cuprous nitrate required to make 1 mL of solution:
Mass of cuprous nitrate required to make 25 mL of solution:
0.375 grams are needed to make 25 mL solution.
