<span>% by mass = mass solute x 100 / mass solution
45.5 % = mass solute NaF x 100 / 34.2
mass solute NaF = 34.2 x 45.5 /100=15.6 g
molae solute NaF = 15.6 g ( 1 mol / 41.9887 g)= 0.372</span>
I'm pretty sure the answer is the first one. The fact that it doesn't have a full valence shell means that electrons from other atoms can react and bond with the sodium atom.
Hope this helps x
Answer:
energy is being used to make or break bonds between molecules
Explanation:
if correct please consider brainliest
The correct answer is:
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" F and Br , because they are in the same group" .
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Note:
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Choice [B]: "F and Br ; because they are in the same period" ; is incorrect; since "F" and "Br" are not in the same "period" (that is, "row").
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Choice [C]: "Na and Mg; because they are in the same group {"column"} ; is incorrect; since: "Na" and "Mg are NOT in the same group {"column"].
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Choice [D]: "Na and Mg" ; because they are in the same period {"row"}; is incorrect. Note: "Na" and "Mg" are, in fact, in the same period {"row"}. However, as aforementioned, {Mg and Na} are not in the same group {"column".}.
Note: The similiarities in physical and chemistry properties among elements are determined and organized — or tend to be so—by "groups" {"columns"} — NOT by "periods" {rows}.
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