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All matter was made up of invisible and indestructable particles.
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Discovered that water was made of hydrogen and oxygen.
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Matter is made up of atoms that are invisible and indestructable. All atoms of an element are identical. Atoms of different elements have different weights and different chemical properties. Atoms of different elements combine in simple whole numbers to form compounds. Atoms cannot be created or destroyed. When a compoind decomposes, the atoms are recovered unchanges.
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Arranged elements into 7 groups with similar properties. discovered the periodic law, which states that properties of elements were periodic functions of their atomic weights.
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Used a CRT to study canal rays, which had electical and magnetic properties opposite of an electron.
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Discovered the electron. designed a signature of electic discharge in a high-vaccum cathode-ray tube.
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Showed that when you heat an object until it glows, you can measure the energy in discrete units that he called quanta.
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Determined the electric charge carried by an electron.
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Nucleus is very dense, very small, and positively charged. also discovered that electrons are located outside of the nucleus, orbiting around the nucleus.
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Wrote papers on the absorption of alpha rays. showed us what a picture of the atomic structure looks like.
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Determined charges on the nuclei of most atoms using x-ray tubes. his discovery that "the atomic number of an element is equal to the number of protons in the nucleus," was used to reorganize the periodic table by atomic number instead of atomic mass.
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Proposed principal of indeterminancy which states that you can't know both the position and velocity of a particle.
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viewed electrons as coontinuous clouds and introduced wave mechanics as a mathematical model of the atom.
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Proved the existence of neutrons by heating nuclei and a elementary particle that had electical charges.
