Atomicness Flashcards
First proposed the theory of the atom, saying they were “uncuttable”
Democritus
He discovered that atoms of different elements are different from others, and that atoms of the same element are the same size. He also discovered that atoms combine in specific proportions and that all substances are made of atoms. To find this out, he worked with gases.
John Dalton
He conducted an experiment with a cathode-ray.Through this, discovered that there are small, negatively charged particles inside an atom. With all this, he proposed the Plum-Pudding Model.
J. J. Thomson
He did an expirement that involved shooting a beam of particles at a thin sheet of gold. Through this he discovered that there is a small, dense, positively charged nucleus; most of an atom’s mass in the atom’s nucleus; atoms contain mostly empty space; electrons move in empty space in the atom.
Ernest Rutherford
. He thought that electrons jumped from level to level, and they travel in definite paths.
Niels Bohr
They determined that electrons paths cannot actually be predicted, and electrons are found in electron clouds, not in definite paths.
Schrodinger & Heisenberg
the smallest particle into which an element can be divided and still be the same substance.
Atom
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All substances are made of atoms. Atoms are small particles that cannot be created, divided, or destroyed.
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Atoms of the same element are exactly alike, and atoms of different elements are different.
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Atoms join with other atoms to make new substances.
Dalton’s Atomic Theory
Negatively charged particle found in every atom
Electrons
Showed electrons were scattered throughout the atom randomly
Plum pudding model
Extremely dense positively charged part of an atom, located in the center
Nucleus
Regions of an atom where electrons are likely to be found
Electron Clouds
