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Energy Levels of an Atom Joseph von Fraunhofer and William Hyde Wollaston
A quantum mechanical system or particle that is bound—that is, confined spatially—can only take on certain discrete values of energy. This contrasts with classical particles, which can have any energy -
Electron Charge
1.60217657 × 10-19 coulombs -
JJ Thomson Dicovers Electrons
Experiments by J.J. Thomson in 1897 led to the discovery of a fundamental building block of matter.The source of these charged particles is a heated cathode that, in fact, causes the atoms of the sample to ionize. These were known as cathode rays. In 1897, Thomson set out to prove that the cathode rays produced from the cathode were actually a stream of negatively charged particles called electrons. -
Discovery of the Nucleus
The nucleus is the very dense region consisting of protons and neutrons at the center of an atom. It was discovered in 1911 as a result of Ernest Rutherford's interpretation of the 1909 Geiger–Marsden gold foil experiment. -
Proton Charge
The proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and mass slightly less than that of a neutron. Protons and neutrons, each with mass approximately one atomic mass unit, are collectively referred to as "nucleons".
1.672621777(74)×10−27 kg[1]
938.272046(21) MeV/c2[1] -
James Chadwick Discovers The Neutron
Chadwick repeated their experiments but with the goal of looking for a neutral particle -- one with the same mass as a proton, but with zero charge. His experiments were successful. He was able to determine that the neutron did exist and that its mass was about 0.1 percent more than the proton's. He published his findings with characteristic modesty in a first paper entitled "Possible Existence of Neutron." In 1935 he received the Nobel Prize for his discovery. -
The Neutron Charge Of Mass
A neutron has no net electric charge and a mass slightly larger than that of a proton. -
The King Is Here
i was born
