Idea-Matter is made of small indivisible particles which have different form, position, and arrangement.
Contribution of the understanding of atom- All matter is made of atoms that have different positions and arrangements.
Idea-The universe is a mechanical universe with small solid masses in constant motion.
Contribtuin to the understanding of atoms-An atom is a solid mass that is able to move.
Idea- Spherical atoms have measureable properties of mass
Contribution to the understanding of atom- Atoms have a measurable mass.
G.J StoneyIdea-Proposed that electricity was made of discrete negative particles, called electrons.
Contribution to the understanding of atom- Electrons have a negative charge.
Experiment- Discovered the electron and used cathode ray tubes to determine the charge to mass ratio of an electron to be 1.759 x 108 coulombs/ gram. He also found canal rays were associated with a proton.
Contirbution to the understanding of atom- Electrons have a charge to mass ratio of 1.759 x 108 coulombs/ gram.
experiment: Used quanta, discrete units of energy to explain glowing hot matter.
Idea:There are flat rings of electrons revolving around a positively charged particle.
Contribution to the understanding of atom-Electrons revolve around the nucleus in rings.
Idea-Determined the charge and the mass of an electron to be 1.602 x 10-19 C and 9.11 x 10-28 g respectively.
Contribution to the understanding of atom-The mass and charge of electrons
Idea-Determined that the nucleus is a small, dense, positively charged part of the atom.
Contribution to the understanding of atom- The nucleus is positively charged and therefore must hold the protons.
Idea-Stated that the atomic number is equal to the number of protons in the nucleus.
Contribution to the understanding of atom-The atomic number is that number of protons in an atom
BohrExperiment- Created a model of successful orbital electron shells.
Contribution to the understanding of atom-Electrons orbit the nucleus in shells.
Experiment- Discovered the neutron by using alpha particles.
Contribution of the understanding of atom- There is a subatomic particle called the neutron.