For the first question the answer is
The "s" orbital can only hold a maximum of two electrons. ... Elements in the each group have the same number of valence electrons. Why is hydrogen set apart by itself? Hydrogen does not belong to a single group b/c it can be considered an alkali metal, but it is also a gas.
The 2 in front of 
in 
is <u>Coefficient.</u>
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The 
after 
in the same equation is <u>sub </u><u>script</u><u>.</u>
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There are two atoms of in 
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Answer:
A.
Explanation:
Squeezing the bottle creates negative pressure inside the bottle because of the plastic's elasticity that will hasten the extraction of the carbon dioxide from the soda.
First find the oxidation states of the various atoms:
<span>in Cr2O2 2- Cr @ +1; In NH3 N @ +3; in CrO3 Cr @ +3, N2 N @ 0 </span>
<span>Note that N gained electrons, ie, was reduced; Cr was oxidized </span>
<span>Now there is a problem, because B has NH4+ which the problem did not, and is not balanced, showing e- in/out </span>
<span>B.NH4+ → N2 </span>
<span>Which of the following is an oxidation half-reaction? </span>
<span>A.Sn 2+ →Sn 4+ + 2e- </span>
<span>Sn lost electrons so it got oxidized</span>
false,
sodium has a vigorous reaction with water.
This can be observed by putting a piece of sodium in water,
it moves swiftly across the surface of water and reacts violently.
