mesozoic era - age of the dinosaurs
end of the paleozoic era - most of earth a desert
end of the mesozoic era - a layer of iridium deposited all over earth
Hypotheisis is just like an initial building block for a building. The true statements about hypothesis among the given are-
- First guess- hypothesis is a proposed explanation for something which is observed. Thus the explanation is just a guess and not a proved one.
- An initial idea which is assumed to be true - The whole experiment or research is based on an assumption which is supposed to be true and the scientist works to prove that true.
The jet stream is a band of reliably strong wind that plays a key role in keeping colder air north and warmer air south. But when the vortex weakens, part of the weakened low-pressure system can break off. This breaking-off process is what causes a polar vortex.
Without that strong low-pressure system, the jet stream does not have enough force to maintain its usual path. It becomes wavy and rambling. When high-pressure systems get in its way, a collection of cold air pushes south, along with the rest of the polar vortex system
Shape and size doesn't affect the density of an object but temperature does affect the density of an object because the molecules act differently in different temps.
Answer:
One change of state happens when you add energy to the substance. This change of state is called melting. By adding energy to the molecules in a solid the molecules begin to move quicker and can break away from the other molecules.
