Term
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Definition
- Number of protons in an atom
- Each element has a unique atomic number
- # of electrons in a neural atom |
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Term
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Definition
- Sum of protons and neutrons
- Mass of an atom
- Subtract the atomic number from it and you get the number of neutrons in the atom (A-Z= number of neutrons) |
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Term
| Two shorthanded notations for the composition of an atom |
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Definition
1)
Mass number
Symbol
Atomic number
2) Name of atom-mass#
EX: Hydrogen-2 |
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Term
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Definition
- Atoms with the same number of protons but dif. Number of neutrons
- Each element has isotopes |
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Term
| Three isotopes of hydrogen |
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Definition
1)1/1H (most common)
a. Called hydrogen-1 or simply hydrogen
2)2/1H
a. Called hydrogen-2 or deuterium
3)3/1 H
a. Called hydrogen-3 or tritium |
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Term
| Isotopes of an element have |
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Definition
1) Different mass numbers
2) Different number of neutrons
3) Same chemical properties because they have the same number of protons and electrons |
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Term
| Dalton's Model of the atom |
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Definition
- A tiny, indestructable, solid sphere
- Had no internal structure |
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Term
| Thomson's Model of the Atom |
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Definition
- A sphere of positive charge with electrons embeaded in it
- Was called the "plum-pudding" model. |
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Term
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Definition
- student of Thomson
- Discovered protons
- Carried out a famous gold-foil experiment
- Rutherford's Nuclear Model of the Atom
○ Tells us that the atoms is
mostly empty space
○ All of the positive
charge and most of the
mass are in a small region
in the center of the
atom called the nucleus
○ Nucleus is composed
of protons and neutrons
○ Electrons moves
around nucleus(outside) |
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Term
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Definition
- Its existence was predicted by Rutherford.
- Has virtually the same mass as a proton, but no change as a proton.
- Was discovered by Chadwick. |
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Term
| three major subatomic particles: |
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Definition
| electron, proton and neutron. |
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Term
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Definition
| each proton and neutron is composed of an even smaller particle called a |
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Term
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Definition
| the smallest particle of an element that retains its identity in a chemical reaction. |
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Term
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Definition
- Was a reek philosopher (460 BC- 370 BC)
- Was among the first to suggest the existence of atoms
- Believed that atoms were indivisible and indestructible.
- Did not carry out experiments |
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