Which statement about the mass of subatomic particles is false?
a)A proton has a mass of 1 amu.
b)A neutron has slightly more mass
than a proton.
C)An electron has slightly less mass
than a proton.
d)none of the above

C

Explanation:

Both proton and neutron have a mass of 1 atomic unit. ( proton positive but neutron no charge) .

even though they both has a mass of 1 amu , they slightly differ in mass. neutron has slightly greater mass than proton .

but electrons are very smaller than protons and neutrons. electron has 1/1840 mass of proton. so they are very smaller than protons.

answer is C

4d^55s^1 ( third choice)