# Homework Help: Ratio between electron to proton

1. Feb 17, 2015

### waver.

1. The problem statement, all variables and given/known data
A 10 gram silver sphere is charged until it acquired a charge of -1.2 coulomb. Find ratio of number of electron to number of proton in spere. Given that silver atomic weight and atomic number 107.87 and 47
2. Relevant equations

3. The attempt at a solution
first i calculated extra electron = -1.2/1.60217657 × 10-19
Since number of proton = number of elelectron before acquired charge . Number of new electron = 47 +1.2/1.60217657 × 10-19.. and then dividing it by 47 . To get the ratio . My question is that correct what i did . And if yes we he mentioned mass of silver and atomic weight.

2. Feb 17, 2015

### Staff: Mentor

What is the old number of electrons of the whole sphere? The sphere has more than one atom and the number of atoms depends on the weight.

3. Feb 17, 2015

### waver.

So 107.87 gm --------->6.0221413*10^23 atom
10 gm ------> x atom
then multiply x with 47 to get whole electrons . Then getting extra electron through q= ne adding it to electron number then dividing it by x*47 (proton) . Is that what you meant

4. Feb 17, 2015

### lightgrav

yes.

5. Feb 17, 2015

### waver.

Well . Thnx for helping . That was kind :)