• Support PF! Buy your school textbooks, materials and every day products Here!

Basic AS level Physics

  • #1
Calculate the mass of an ion that has a specific charge of 1.20x10^7 C kg^-1 and a negative charge of 3.2x10^-19 C.

Textbook answer: 2.67x10^-26 kg.

Question: if the ion has a negative charge of 3.2x10^-19, isn't that -3.2x10^-19?! In which case the answer would be -2.67x10^-26 kg?! Is the use of the word negative in this question a bit misleading?
 

Answers and Replies

  • #2
2,442
87
Hello Dan.West Ham supporter here(don't take the mickey).You make an interesting point.Specific charge is a ratio and I dont recall having seen it given either a positive or negative label.Thinking about it,it might seem to be more instructive to do so.
 
  • #3
Hi Dadface, it isn't actually the specific charge I'm concerned about, its the charge of the ion. Is 'a negative charge of 3.2x10^-19 C' the same as -3.2x10^-19 C?! In which case the answer would be -2.67x10^-26 kg?! Is the use of the word negative in this question just a bit misleading?

Thanks very much!

P.s. Just watching the Bolton game myself!
 
  • #4
2,442
87
Yes it is the same and it is twice the charge of the electron.From its charge and mass it looks like it's an oxygen ion.
 

Related Threads for: Basic AS level Physics

  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
1
Views
2K
Replies
1
Views
1K
Replies
3
Views
2K
Replies
5
Views
534
Replies
1
Views
3K
  • Last Post
2
Replies
40
Views
4K
Top