# Why is there a negative charge on the oxygen atom with the single bond?

1. Nov 24, 2017

### Indranil

• Please post this type of questions in homework section using the template.
2. Nov 24, 2017

### BvU

Count the electrons ... (use factor 0.5 for shared electrons)

3. Nov 24, 2017

### Indranil

I don't understand what you mean. Could you make your point easier, please? Could you tell me the method, please?

4. Nov 25, 2017

### Staff: Mentor

For each atom count electrons "belonging" to that atom, if an electron is shared by two atoms, count it as half.

5. Nov 25, 2017

### Indranil

Still, I don't understand how to count. Could you clarify it, please?

6. Nov 26, 2017

### Staff: Mentor

Each dot is a single electron, each bar is a bond - so two shared electrons.

How many dots on the left atom? How many shared electrons on the left atom? Just add.

7. Nov 27, 2017

### Indranil

If I count from the left atom with the double bond, 4 dots, and two shared electrons, total electrons are 8. now what to do next, sir?

8. Nov 27, 2017

### Staff: Mentor

4+2 is not 8.

How many electrons should be present on the valence shell in a neutral, isolated oxygen atom?

9. Nov 27, 2017

### Indranil

It should be 6 electrons. Now what to do next, sir?

10. Nov 27, 2017

### Staff: Mentor

Don't "sir" me.

As I wrote - your calculations are off, correct them. And use the same approach to calculate number of electrons on other oxygen atoms.

11. Nov 27, 2017

### Indranil

Still, I am confused. Could you calculate, please?

12. Nov 28, 2017

### Staff: Mentor

I am not going to spoon feed you, sorry. You will either try, or you will not learn anything.

13. Nov 28, 2017

### Indranil

How to try. could you give me some formula?.

14. Nov 28, 2017

### Staff: Mentor

What formula do you need to count the dots on the picture?

15. Nov 29, 2017

### Indranil

Formal charge.

16. Nov 29, 2017

### Staff: Mentor

I have no idea what you mean now.

You were told to count electrons, you even did it - you just made a trivial mistake when adding two numbers. Please reread the thread, you were told what to do several times. If you know what the dots and bars on the resonance structure are the task is trivial.