# How to calculate the mass of a hydrogen atom

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1. Sep 16, 2015

### reemie

• Please post this type of questions in HW section using the template.
The answer according to my booklet is 1.6734×10-24 (g), but I don't understand how we got this answer.

proton: 1.6725×10-24
neutron: 1.6748×10-24
electron: 0.0009×10-24

To get the mass, I added protons with neutrons, but I got 3.3473×10-24.

What am I doing wrong?

2. Sep 16, 2015

### Staff: Mentor

Why do you think there is a neutron present?

3. Sep 16, 2015

### reemie

Because the mass number is the sum of protons and neutrons, correct?

Edit:

I realised that hydrogen doesn't have any neutrons, so we should only consider the protons. But that still gives the wrong answer.

And when I subtract the number of protons from the answer, I get 9x10-28, and I can't figure out where this number came from.

Last edited: Sep 16, 2015
4. Sep 16, 2015

### SteamKing

Staff Emeritus
Do you think that the mass of a hydrogen atom might be affected by the presence of another particle, perhaps? Hint: Look at the list in the OP.

5. Sep 25, 2015

### Neon

Hello? The hydrogen you created is a postively charged atom a which not good. soo