# Qns On Protons

1. ### Delzac

389
Hi,

Given that a " up " quark has charge of 2/3e ; a "down" quark has a charge of - 1/3e, where e is the elementary charge (+1.6 x 10^-19 C).

can is say that a proton contain 3 " up " quark and 1 "down" quark?

the charge in the end seems to add up to +1.

is what is have said correct?

p.s. i just started learning particle physics

2. ### neutrino

(3 x 2/3) + (1x(-1/3)) = 1?

Incase you meant 3 down quarks, then that doesn't work either - Add the masses of the quarks.

3. ### jhmar

77
Charge values are: u = +2/3; d = -1/3
2 up + 1 down = +1

Last edited: May 17, 2006
4. ### Delzac

389
sry i meant 2 " up" quarks and 1 " down" quark. does it work now?

5. ### Delzac

389
another thing i understand is that quarks isn't actually IN the proton itself isn't? so how can we say that to proton CONTAIN quarks IN it

1,811

7. ### dav2008

624
The proton is made up of quarks.

There aren't quarks "inside" of a proton because that implies there exists a structure called a proton independently of quarks.

Edit: Well I guess there are also gluons.

Last edited: May 21, 2006
8. ### Lyuokdea

198
Summing the masses wouldn't give you any useful information for finding the number of quarks in a proton or neutron, without a lot of extra information. The sum of the quark masses is only a small percentage of the mass of a proton.

~Lyuokdea

9. ### neutrino

I had this feeling that my teacher was wrong. :grumpy: I should've checked what he said, though. I stand corrected...Thanks.