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Early Atomic Theory
Early Atomic Theories
Question | Answer |
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The concept of the atom goes back more than 2,000 years, to the Greek philosopher [...]. | The concept of the atom goes back more than 2,000 years, to the Greek philosopher Democritus. |
[...] hypothesized the existence of particles he called atomos, which is Greek for "not-cutable." | Democritus hypothesized the existence of particles he called atomos, which is Greek for "not-cutable." |
[...]'s experiments showed that matter is neither gained nor lost in a chemical reaction. | Lavoisier's experiments showed that matter is neither gained nor lost in a chemical reaction. |
In the 1800s, John [...], an English scientist, came up with an atomic theory of matter. | In the 1800s, John Dalton, an English scientist, came up with an atomic theory of matter. |
Dalton described the relationship between [...] and their atoms. | Dalton described the relationship between elements and their atoms. |
Thomson proved that [...] charged particles were parts of atoms. | Thomson proved that negatively charged particles were parts of atoms. |
[...] determined that all atoms have electrons. | Thomson determined that all atoms have electrons. |
Thomson determined the [...]-to-mass ratio of an electron. | Thomson determined the charge-to-mass ratio of an electron. |
Thomson's hypothesis that an atom was a swarm of electrons in a mass of positive substance is called the plum pudding model of the atom. | Thomson's hypothesis that an atom was a swarm of electrons in a mass of positive substance is called the plum pudding model of the atom. |
The mass of an electron was determined by an ingenious '[...] drop' experiment done in 1909 by Robert Millikan. | The mass of an electron was determined by an ingenious 'oil drop' experiment done in 1909 by Robert Millikan. |
Milikin used Thomson's charge-to-mass ratio of the electron to calculate its [...]. | Milikin used Thomson's charge-to-mass ratio of the electron to calculate its mass. |
The mass of an electron was determined by an ingenious 'oil drop' experiment done in 1909 by Robert [...]. | The mass of an electron was determined by an ingenious 'oil drop' experiment done in 1909 by Robert Millikan. |