Answer:
can u give us the options
<span>Helium is the noble gas with only 2 valence electrons
I Hope This helps
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Answer:
a chemical reaction or other process in which the products themselves promote or spread the reaction, which under certain conditions may accelerate dramatically.
Explanation:
the self-sustaining fission reaction spread by neutrons which occurs in nuclear reactors and bombs.
a series of events, each caused by the previous one.
Answer: -
After rain fall occurs, water accumulates
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This water is called ground water. This water slowly flows under the ground through the pore spaces in the soil. The water continues to go under the soil till it reaches a certain point where it can no longer go down.
In this region the water slowly accumulates forming a water reservoir called aquifer. The aquifer is a place under the soil which is saturated with water. The upper surface of this zone of saturation is called the water table.
