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25 Cards in this Set
- Front
- Back
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What is an allegory? |
A story, poem, or picture that can be interpreted to reveal a hidden meaning, typically a moral or political one. |
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Who was Democritus? |
A Greek philosopher, came up with the idea of atmos(atoms), believed that atoms are solid, indestructible, and indivisible. |
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Who was Aristotle? |
A Greek philosopher, he believed empty space cannot exist, and that matter is made up of earth, fire, air, and water. |
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Who was John Dalton? |
An English school teacher, believed matter is composed of extremely small particles called atoms, and that atoms are indivisible and indestructible. |
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Who was Sir William Crookes? |
An English physicist, credited with the discovery of the electron, and invented cathode ray tube. |
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Who was J.J. Thomson? |
An English physicist, he worked on mass to charge ratio, and invented plum pudding model. |
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Who was Robert Millikan? |
An American physicist, he determined the charge of an electron using the oil drop apparatus. |
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Who is Ernest Rutherford? |
A New Zealand physicist, created Gold Foil Experiment. By 1920, he refined his concept of the nucleus to include protons. A proton has a mass of 1 amu and a charge of +1. |
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Who was James Chadwick? |
An English physicist, showed that the nucleus contains a neutron. A neutron has a mass of 1 amu and has a neutral charge. Won Nobel Prize for proving existence of neutrons. |
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How much percent of the mass of an atom is found in the nucleus? |
99.97% |
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Who was Henry Mosley? |
An English scientist, discovered that atoms have a unique number of positively charged particles and he named it atomic number. |
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What is an isotope? |
Atoms with the same number of protons but different numbers of neutrons. |
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What is a mass number? |
The sum of the atomic number and neutrons in the nucleus. |
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What is atomic mass unit defined as? |
1/2 the mass of a carbon 12 atom. |
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What is atomic mass defined as? |
The weighted average mass of the isotopes. |
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What is isotope abundance? |
The elements mass indicates the abundance of the isotope. |
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What is radioactivity and when was it discovered? |
It is spontaneously omitted radiation. It was discovered in the 1980's. |
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What is radiation? |
Rays and particles omitted by a radioactive material. |
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What is a nuclear reaction? |
A reaction that involves a change in the atoms nucleus. |
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What is radioactive decay? |
Unstable nuclei lose energy by omitting spontaneous radiation. |
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What is alpha radiation? |
Radiation is deflected toward a negatively charged plate. |
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What is an alpha particle? |
Contains 2 protons and 2 neutrons and this has a charge of 2+. |
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What is beta radiation? |
Radiation is selected toward a positive plate. |
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What is a beta particle? |
An electron with -1 charge. |
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What is a gamma ray? |
A high energy radiation that possesses no mass and no charge. |
