D. Electrons orbit in a fixed shell
To determine whether the amount of H2 in the lab is dangerous, we first need to know how much hydrogen gas is present in the room in units of percent by volume. For this particular problem, we cannot exactly determine since we do not know the total volume of the room. Hope this answers the question.
Answer:
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Explanation:
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This is the answer
The elements potassium and sodium have similar chemical properties because they have the same number of valence electrons and form +1 ions.
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