3- Give the number of protons and electrons in each of the following common ions:

Na+ , Ca2+ , Fe2+ , Fe3+ , Mg2+ , Mn2+ , Cu2+ , I- , F- , S2- , O2- , N3- , Br- , C4-

I'll tell you, this is very easy!

Remember that:
# of protons = # atomic number
Proton remain constant despite the species' charge because its inside the nucleus. It is only the electron which is varied in the species. This is termed as ions.
If the charge is positive, it means it lacks electron/s (if +, then - electron)
If the charge is negative, it means that it has extra electron/s (if -, then + electron)

So,
Na+ : atomic # = 11
# of protons = 11
# of electrons = 10

Ca+2 : atomic # = 20
# of protons = 20
# of electrons = 18

Fe+2 : atomic # = 26
# of protons = 26
# of electrons = 24

Mg+2 : atomic # = 12
# of protons = 12
# of electrons = 10

Mn+2 : atomic # = 25
# of protons = 25
# of electrons = 23

Cu+2 : atomic # = 29
# of protons = 29
# of electrons = 27

I- : atomic # = 53
# of protons = 53
# of electrons = 54

F- : atomic # = 9
# of protons = 9
# of electrons = 10

S-2 : atomic # = 16
# of protons = 16
# of electrons = 18

O-2 : atomic # = 8
# of protons = 8
# of electrons = 10

N-3 : atomic # = 7
# of protons = 7
# of electrons = 10

Br- : atomic # = 35
# of protons = 35
# of electrons = 36

C-4: atomic # = 6
# of protons = 6
# of electrons = 10

Look on the periodic table for each of those elements. Write down the Atomic number for each of them. The atomic number equals the number of protons.

SO for protons: just write the number down that on the table. For electrons if the sign is + you subtract 1 if the sign is - then you add one to the atomic number for than element.
Na=11 11-1= 10
Ca=20 20-2=18
Fe=26 26-2=24
Fe=26 26-3=23
Mg=12 12-2=10
Mn=25 25-2=23
Cu=29 29-2=27
I=53 53+1=54
F=9 9+1=10
S=16 16+2=18
O=8 8+2=10
N=7 7+3=10
Br=35 35+1=36
C=6 6+4=10

Just look at the periodic table. If it's +x, go to the left x spaces. Opposite for anions.