click below
click below
Normal Size Small Size show me how
Nuclear Physics
LC Physics (Radioactivity and Nuclear Energy)
Term | Definition |
---|---|
Emission Spectrum | Pattern formed when light undergoes dispersion. |
Continuous Spectrum | Pattern produced by an incandescent solid/liquid where all visible wavelengths are present. |
Emission Line Spectrum | Pattern produced when light from an excited gas is passed through a diffraction grating/prism. It consists of a series of bright lines on a dark background unique to each element. |
Absorption Line Spectrum | Pattern produced when light from an incandescent source is passed through a gas. A series of darks lines is observed on a visible spectrum. |
Energy Level | Fixed energy value that an electron can have in an atom. |
Atomic Number | Number of protons in an element. This is also the number of electrons in an element. |
Mass Number | Number of neutrons and protons in an element. |
Isotope | An atom of an element that has the same number of protons but a different number of neutrons to that element. |
Radioactivity | The disintegration or decay of the nucleus of certain atoms with the emission of one or more types of radiation. |
Three Type of Radiation | 1. Alpha 2. Beta 3. Gamma |
Alpha Particle | Fast moving helium nucleus ejected from the nucleus of a radioactive atom. |
Beta Particle | High speed electron ejected from the nucleus of a radioactive atom. With beta emission a neutron splits into a proton and an electron. |
Gamma Radiation | Very high frequency electromagnetic radiation. |
Activity | Number of nuclei of a radioactive substance decaying per second. |
1 Becquerel | 1 radioactive disintegration per second. |
Law of Radioactive Decay | The number of nuclei decaying per second is directly proportional to the number of undecayed nuclei. |
Half-life | The time taken for half of the undecayed nuclei atoms to undergo decay. |
The Mole | Amount of a substance that contains as many particles as there are atoms in exactly 12 grams of Carbon-12. This amount is Avogadro's number 6.02 x 10^23. |
Nuclear Fission | The splitting of a nucleus into two smaller nuclei of roughly the same size with the release of neutrons and energy. |
Nuclear Fusion | The fusing of two smaller nuclei to form a larger nuclei with the release of neutrons and energy. |
Moderator | Slows neutrons down in a nuclear reactor to produce further fission. Graphite or heavy water is used. |
Control Rods | Absorb neutrons to slow down nuclear fission in a nuclear reactor. Made from steel with cadmium or boron. |
Shielding | Stops radiation escaping from a nuclear reactor. Usually lead or concrete. |