Atomic and Nuclear Physics Flashcards
Atom
The smallest part of an element that can exist on its own
Charge
The property that causes electrical effects
Plum pudding model 🧁
Negative electrons spread throughout the atom like currents in a bun - positive charge that we spread throughout the atom 🧁
Observations for Rutherford nuclear experiment
- most of the particles went straight through the foil
- A few alpha particles were slightly deflected
- Some were deflected through very large angles
- 1 in 8000 were “back scattered”
radioactivity
radioactivity is the process that occurs when alpha particles, beta particles or gamma waves are emitted from an unstable nucleus
alpha particles
the helium nuclei containing two protons and two neutrons which are emitted by radioactive nuclei
beta particles
beta particles are fast-moving electrons emitted by radioactive nuclei
gamma radiation
gamma radiation is a high-energy electromagnetic wave emitted by radioactive nuclei
Nature of alpha particle
Each particle is two protons, and two neutrons nucleus of helium – 4
Source of alpha particles
A radioactive nucleus
Relative charge of an alpha particle compared with charge on proton
+2
Mass of alpha particle compared with beta
High
Speed of alpha particle
Up to 0.1 x speed of light
Ionising effect of alpha particle
Strong 💪
Penetrating effect of alpha particle
Very low penetrating power, stopped by a few cms of air or thin tissue paper
Nature of beta particle
A fast electron
Source of beta particle
A radioactive nucleus
Beta particle relative charge compared with the charge on a proton
–1