Answer:
C
Explanation:
If you move the decimal to the left it transforms the expression into scientific notation.
Explanation:
Each atom type contains the same number of protons. Chemical bonds link elements together to form more complex molecules called compounds. A compound consists of two or more types of elements held together by covalent or ionic bonds
Answer:
613 mg
Explanation:

Number of fargday's 
Here, I = 9.20 A
t = 10.5 min
= 10.5 x 60 seconds
So, 

= 0.0208 F
Here, 2e, 2F
2F = 1 mol of Ni

1 mol = 59 gm of Ni
0.0104 mol = 59 x0.0104 gm Ni
= 0.613 gm Ni
= (0.613 x 1000 ) mg of Ni
= 613 mg of Ni
I think its density is 850kg/m^3