The answer for 21 I think is false
It really is impossible to predict such a matter. I mean, think about it, its nearly impossible to think about how earth would be impacted if the heat from the interior of the planet that powers plate tectonics were to suddenly cease to exsist, or if that heat never exsisted in the first place, because that is how planets are formed.
One thing is certain however, life wouldn't be the same without plate tectonics; in one case, the constont transgression/regression, sue in large part of tectonic forces acts as a evolutionary pump forcing life to evolve. EXAMPLE: the evolution of plants from marine to terrestrial settings. Without plate tectonics, life would certainly be dramatically different.
~This is an edgucated guess. :) I hoped i helped. :)
Answer:
chemical change.
Explanation:
There are two types of changes in matter: physical change and chemical change.
physical change- it is a change in matter that alters only its physical properties or its physical appearance. This type of change is reversible. For example- freezing of water, the water turns into solid ice and it can be reversed by melting the ice.
chemical change- it is a change in matter that alter its chemical and thus its physical properties. Most chemical changes are irreversible. for example- burning of paper, results in black soot and ashes- Thus changing both physical and chemical properties.
