Answer:
Na ·
Explanation:
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In this case, since the Lewis dot structure of any element illustrates the number of valence electrons at the outer shell; we can set up the electron configuration of sodium to obtain:

We can see there is only one valence electron, for that reason the Lewis dot structure is:
Na ·
Whereas the dot represents the valence electron.
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Answer:
If you are meaning O2^2- ion, well, don’t forget that ions have a charge, that has to be specified when referring to them. It is a polyatomic ion just because it consists of more than one atom, irrespective of the fact that these atoms are of the same element or not. It was given that name because at the early times chemistry was founded as a science, it was found that with respect to other oxygenated substances, peroxides contained more oxygen than expected: Latin prefix per- gives the terms it is attached to the meaning of being increased, enhanced, and similar.
Explanation:
Answer: 116 g of copper
Explanation:

where Q= quantity of electricity in coloumbs
I = current in amperes = 24.5A
t= time in seconds = 4.00 hr =
(1hr=3600s)

of electricity deposits 63.5 g of copper.
352800 C of electricity deposits =
of copper.
Thus 116 g of Cu(s) is electroplated by running 24.5A of current
Thus remaining in solution = (0.1-0.003)=0.097moles
Both A and B are the answer.
Answer:
Final mass = 159.5 g
Final temperature = 10 C
Final density = 1.00 g/ml
Explanation:
<u>Given:</u>
Beaker 1:
Mass of water = 44.3 g
Temperature = 10 C
Beaker 2:
Mass of water = 115.2 g
Temperature = 10 C
Density of water at 10C = 1.00 g/ml
<u>To determine:</u>
The final mass, temperature and density of water
<u>Calculation:</u>

Since there is no change in temperature, the final temperature will be 10 C
Density of a substance is an intensive property i.e. it is independent of the mass. Hence the density of water will remain constant i.e. 1.00 g/ml