There are negatively charged particles embedded in the "positive soup"
The atom is mostly empty space, with nearly all of its mass concentrated in a tiny central nucleus The nucleus is positively charged and surrounded at a great distance by the negatively charged electrons
Energy is transferred only in certain well defined quantities Electrons should move around the nucleus but only in prescribed orbits When jumping from one orbit to another with lower energy, a light quantum is emitted.
We cannot measure the position (x) and the momentum (p) of a particle with absolute precision The more accurately we know one of these values, the less accurately we know the otherWe call this the Uncertainty principle
After doing my experiment, I (James Chadwick) have hound neutral charged particle with the approximate mass of a proton. They are called neutrons