CK-12 Foundation
Ck 12: Chemistry: Protons
[Free Registration/Login may be required to access all resource tools.] Describes research on the proton and the determination of the weight of proton and electron.
Sophia Learning
Sophia: Subatomic Particles: The Proton: Lesson 2
This lesson will explain that protons are positively charged particles having a mass of one amu and are found in the nucleus of the atom. It is 2 of 3 in the series titled "Subatomic Particles: The Proton."