Nuclear And Particle Physics Flashcards
(7 cards)
What was Rutherford’s Alpha Scattering experiment?
High speed alpha particles were fired at a very thin sheet of gold foil
What were the observations and conclusions made from Rutherford’s Alpha Scattering experiment?
Most of the α-particles went straight through the gold foil:
This suggested that most of the atom is empty space
Some α-particles were deflected at large angles:
This suggested that there is a positive nucleus in the centre
A few α-particles deflected straight back:
This suggested that the nucleus is very small and it is where the mass and the charge of the atom is concentrated
How has our understanding of the atomic structure changed over time?
Dalton suggested that all matter is made of tiny, solid, indivisible particles called atoms
Thomson discovered the electron and proposed the ‘Plum Pudding Mode’ (a positively charged sphere with electrons embedded throughout)
Rutherford proposed the ‘Nuclear Model’ after a series of Alpha Scattering experiments
Bohr suggested that electrons orbit the nucleus in discrete energy levels
The Quantum Mechanical Model outlined how electrons do not orbit the nucleus in specific fixed shells, but rather described the probability of finding electrons in three-dimensional regions of space, called orbitals
Chadwick discovered the neutron, explaining the previous discrepancy surrounding the proton number/mass number disparity
What is the nucleon number?
Total number of neutrons and protons in the nucleus of an atom
What is the proton number?
Total number of protons in the nucleus of an atom
What is an isotope?
An atom (of the sane element) that has an equal number of protons but a different number of neutrons
What is thermionic emission?
When conduction electrons are released from a metal surface due to heating
When a metal is heated, the conduction electrons within it gains sufficient kinetic energy to leave its surface
