Primary succession is when, for example, a volcano explodes and there is nothing left and even the soil is ruined. It would take at least a hundred years for the land to be like it was before the volcano erupted. Secondary succession is when, for example, a wild fire happens but the soil is not ruined. It would take at least 25-50 years for the land to be like it was before the fire.
Answer:
Trees and plants.
Explanation:
Trees give us oxygen and plants get rid of carbon dioxide and remake it as oxygen.
Your wording is a bit confusing, but I get what you're trying to say.
Here's what the life cycle of a star looks like.
Stars begin as giant balls of hydrogen colliding together and releasing a ton of energy. This hydrogen will eventually fuse together to form helium, and once all of the hydrogen has become helium, This helium will, after a very long time and under lots and lots of pressure, form carbon. When this happens, it is considered a red giant, and the star becomes bigger and less bright. The star will become less and less bright and eventually start to shrink as all of that carbon turns to heavier elements like iron, turning into a dwarf star that eventually dies out.
(Dwarf stars are still shining are called white dwarf stars, and dead ones are black)
The cool part, though, is that massive stars (those which have a mass of at least 3 times the Sun's) turn into heavy elements so fast that the core collapses almost instantaneously and explodes violently into a ball of fire known as a supernova.
Sometimes the core of the star gets left behind, and either forms a neutron star or, if it has the mass of a massive star, will collapse in on itself and become a black hole.
Answer:
120 m/s
Explanation:
formula is displacement by time
v=s/t
v= 3600/30
v= 120m/s
