Answer:
Some of the hydrogen bonds with other elements, but most of it remains free hydrogen. Both hydrogen and helium are light elements, so they will tend to evaporate into space over time. ... But the gravity of Earth isn't strong enough, so Earth's early atmosphere of helium and free hydrogen evaporated into space.
Explanation:
Answer is: the part of an experiment that stays the same though out the experiment is constant.
<span>Constant is a quantity that does not change.
</span>Experimental variable<span>, which is the also part of an experiment, is affected by the experiment (have change).</span>
Answer:
C) OXIDATION
Explanation:
Oxidation is the reaction of a substance with oxygen. When a rock reacts with oxygen, it forms iron oxide, which weakens the rock.
Respiratory system, excretory system, digestive system
