101 حقيقة في الفيزياء

Nuclear Physics



84- Alpha particles are the same as helium nuclei and have the symbol .
85- The atomic number is equal to the number of protons (2 for alpha)
86- Deuterium () is an isotope of hydrogen ()
87- The number of nucleons is equal to protons + neutrons (4 for alpha)
88- Only charged particles can be accelerated in a particle accelerator such as a cyclotron or Van Der Graaf generator.
89- Natural radiation is alpha (), beta () and gamma (high energy x-rays)
90- A loss of a beta particle results in an increase in atomic number.
91- All nuclei weigh less than their parts. This mass defect is converted into binding energy. (E=mc2)
92- Isotopes have different neutron numbers and atomic masses but the same number of protons (atomic numbers).
93- Geiger counters, photographic plates, cloud and bubble chambers are all used to detect or observe radiation.
94- Rutherford discovered the positive nucleus using his famous gold-foil experiment.
95- Fusion requires that hydrogen be combined to make helium.
96- Fission requires that a neutron causes uranium to be split into middle size atoms and produce extra neutrons.
97- Radioactive half-lives can not be changed by heat or pressure.
98-One AMU of mass is equal to 931 meV of energy (E = mc2).
99- Nuclear forces are strong and short ranged.