Term
Nucleus
(made of...)
(charge...)
(mass...) |
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Definition
The dense core of the atom.
Protons and neutrons.
Positive
1 atomic mass unit |
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Term
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Definition
Number of protons in the nucleus
aka atomic number |
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Term
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Definition
| Number of protons plus neutrons in the atom. |
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Term
Neutron
(charge...)
(mass...) |
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Definition
Particle in the nucleus
Neutral
1 atomic mass unit |
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Term
Proton
(charge...)
(mass...) |
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Definition
Particle in the nucleus
Positive charge
1 atomic mass unit |
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Term
Electron
(charge...)
(mass...) |
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Definition
Particle orbiting nucleus
Negative charge
1/2000 atomic mass unit |
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Term
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Definition
| Nuclei which have the same number of protons |
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Term
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Definition
| Unstable nucleus which will decay spontaneously into another element |
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Term
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Definition
When an unstable nucleus spontaneously emits a particle.
Also called disintegration. |
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Term
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Definition
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Term
Alpha particle
(charge...)
(mass...) |
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Definition
Emitted by unstable atom. Same as He nucleus.
Positive charge (+2)
4 atomic mass units |
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Term
Beta particle
(charge...)
(mass...) |
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Definition
Emitted by unstable atom. Fast electron.
Negative charge
1/2000 atomic mass unit |
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Term
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Definition
Emitted from nucleus with alpha or beta particles
High energy electromagnetic wave
NOT a particle |
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Term
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Definition
Electrons knocked off gas atoms by nuclear radiation
Alpha the most, Gamma the least. |
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Term
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Definition
Nuclear radiation passing through matter
Gamma the most; Alpha the least |
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Term
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Definition
Radiation in the environment from natural sources
Must be subtracted from readings during an experiment |
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Term
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Definition
A measure of the particles emitted per second from a source. Falls with time.
Unit = bequerel |
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Term
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Definition
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Term
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Definition
The average time for half of the atoms in a sample to decay
OR average time for the activity to fall by half |
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Term
| Four uses of radioactivity |
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Definition
Sterilisation
Tracers
Radiotherapy
Dating in archaeology |
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Term
| Three dangers of radioactivity |
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Definition
Radioactive waste
Cell damage
Mutations |
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Term
| Rutherford, Geiger, Marsden experiment |
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Definition
| Alpha particles deflected by gold atoms suggested nuclear model |
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Term
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Definition
| Uranium-235 split into daughter nuclei by neutron collision |
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Term
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Definition
| Neutrons from fission reaction cause new fission |
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Term
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Definition
Neutron absorbers can stop fission reaction
eg boron, cadmium |
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Term
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Definition
Slows fast neutrons to enable fission
eg graphite, heavy water |
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Term
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Definition
Transfers heat energy from reactor core
eg water, carbon dioxide, liquid sodium |
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