[Stitch]

          Determine the relative electrical charge of the X element ion , knowing that 12,8 g of X element accepts  4.8176 x 10**23  electrons and that the weight of an atom of the X element= 53,12 x 10 ** -24g. 
                       *delete me*   I am a stuend in high-school, the first year!
                                    Thank you a lot of you can help me! 
                 
                                                   Stitch
       
                       

[AWK]

From mass of atom calculate  molar mass of this atom ( use Avogadro number).
Having know this mass you can calculate moles of electrical charges in 1 mole of atoms. This number  is also the charge of this atom.

[Stitch]

         I shall say:
     X...yg...6.023 x 10**23
      12.8g...53,12 x 10 ** -24g
             And I will calculate y.
             Then I will do ->  y-z=12.8g

           Or I shall do: (53,12 x 10 ** -24g) +   4.8176 x 10**23  = ?

                   HELP ME!
           I am a student in the 9th grade, a little chimist  ....!

[Padfoot]

Then I will do ->  y-z=12.8g

I'll get you started:

mass of atom * Avogadro's number = molar mass
12.8/molar mass = number of moles

[Stitch]

         So.. I will do 12.8/6.023 x 10**23= 2,125 x 10-23
                        -> 2e >>>> X 2-

[Padfoot]

         So.. I will do 12.8/6.023 x 10**23= 2,125 x 10-23
                        -> 2e >>>> X 2-

No, I'll walk you through it:

The mass of 1 atom (of element X) is given.
Molar mass is the mass of 1 mol (6.022 x 10²³) atoms. 
So the molar mass= mass of 1 atom x (6.022 x 10²³)
                       
Now, we have 12.8g so this means (12.8/molar mass) mol of element X.

Number of electrons accepted = 4.8176 x 10²³
This means:
Number of mol of electrons accepted = (4.8176 x 10²³)/Avogadro's number)

Dividing the value above by amount of element X (underlined) gives the number of electrons (in mol) accepted by each mol of element X

As AWK exaplined originally this is the same as the charge on the X ion.

Hope that Helps 

[Stitch]

              Thank you very much!