-
John Dalton
Dalton created the "Billard Ball" model. He defined the atom to be a ball like structure. He studied the laws of chemical combinations and characteristics of atoms. He symbolized atoms and created the "Daltons Law". The "Daltons Law" is the total pressure of mixture of gasses amounted to sum of partial pressures that each individual gas exerted while occupying the same space. -
JJ Thomson
JJ Thomson's experiments showed all atoms contain negatively charged subatomic particles or electrons. And the matter inside of the nucleus is positively charged. -
Ernest Rutherford
He shot particles through a gold sheet. Most of the particles went straight through, this shows that the bulk of the atoms are empty space. Some particles were deflected away, this shows that the nucleus is small and has a positive charge. A few particles bounced back showing that the nucleus is dense. -
Niels Bohr
He proposed the theory that hydrogen atoms transferred only in well defined quantities. He proposed that the nucleus was positively charged and the electrons orbited around the nucleus. This is called the Earth Model. -
James Chadwick
James Chadwick discovered the neutron. A neutron is a particle with no electric charge that, along with positively charged protons, makes up an atom's nucleus. He was able to give evidence about isotopes. Isotopes with the same element number have the same number of protons and electrons but a different number of neutrons found in the nucleus.
