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35 Cards in this Set
- Front
- Back
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Democritus |
- Ancient Greece - 400 B.C
- First proposed idea of an atom
- Atoms were indivisible, indestructible - smallest pieces of matter possible
-No scientific testing or proof |
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John Dalton |
- School teacher in England
- Performed experiments
- Studied ratios in chemical combinations
- Dalton Atomic Theory |
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J.J Thomson |
- "Plum Pudding" Model
- Discovered the electron
- Tiny charged particle
- Cathode ray experiment
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E. Goldstein |
- Cathode ray experiments - Canal rays
- Travelled in the opposite direction as cathode rays
-Protons - Positively charged particles |
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James Chadwick |
- Discovered third subatomic particle -Neutron - Uncharged particle |
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Earnest Rutherford |
- Gold foil & alpha particle experiment - Most passed through - Some large angles - Some came right back - Modern atomic model |
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Atom |
- Smallest particle of an element that keeps its properties
- Mostly empty space
-Size - All copper penny |
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Proton |
- Positively charged particles
- Reside in the nucleus |
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Electron |
- Negatively charged particle - Reside outside the nucleus |
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Neutron |
- Uncharged particles
- Reside in the nucleus |
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Ions |
- Atoms lose / gain 1 or more electrons |
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Neutrons Lose... |
- # protons > # electrons
- Positive |
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Neutrons Gain... |
- # protons < # elctrons
- Negative |
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Mass Number |
- Mass concentrated in nucleus
- Two particles - Protons & Neutrons |
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Isotopes |
- Atoms of the same element with different # of neutrons |
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Atomic Mass |
- The actual mass of an atom |
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What is the purpose of the Periodic Table? |
- A systematic logical way of organizing the elements |
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J. W. Dobereiner |
- Grouped elements in "triads" |
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Dmitri Mendeleev |
- Father of the periodic table
- Arranged elements by increasing atomic mass |
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Henry Mosely |
- Determined atomic # of elements
- Arranged periodic table by atomic #
- Modern Periodic Table |
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Period |
- Horizontal rows on the periodic table |
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Group |
- Vertical elements on the periodic table |
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What are the three types of elements? |
- Metals
- Non - Metals
- Metalloids |
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Transition Metals |
- A lot of common Metals |
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Transition |
- React in a variety of ways |
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Inner Transition Metals |
- Rare earth metals |
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Periodic Law |
- There is a periodic repetition of the element's |
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Alkaline Earth Metals |
- Second column
- Soft Metals |
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Alkali Metals |
- Far left column
- Soft, highly reactive metals |
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Group 3A, 4A, 5A, & 6A |
- Groups contain some metals, nonmetals, & metalloids |
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Hallogens |
- Mostly gases
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Bromine |
- liquid & gas at the same time |
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Iodine |
- Solid & gas at the same time |
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Noble Gases |
- All gases |
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Noble |
- Stable; they don't form compounds
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