Definitions Flashcards
Alpha
A helium nucleus (4-2-He)
That moves only a few cm in air and cannot penetrate skin
Very ionising
Nucleon
particles found in the nucleus- protons and neutrons
Beta +
Fast moving positron
Decreases proton number by 1 in Beta+ emission
Beta -
Fast moving electron
Increases proton number by 1 in Beta- emission
Gamma
High frequency/energy Electro-Magnetic wave (travels at the speed of light, highly penetrating, not very ionising)
(Cannot be completely stopped, only slowed or reduced)
Fission
The splitting on large unstable nuclei to form smaller more stable nuclei
Fusion
The joining of 2 small nuclei to form bigger, more stable nuclei
Binding energy
The energy required to break a nucleus into its constituent parts
Mass Defect
The difference in mass between the nucleus and its constituent parts
Random (in terms of decay)
You cannot predict which nucleus will decay NEXT
Spontaneous (in terms of decay)
Cannot be influenced by external factors (e.g. Temperature)
So we cannot control the speed or amount of decay
Half life
The amount of time it takes for half of the undecayed nuclei to decay
Isotope
An atom with the same number of protons, different number of neutrons
SHM (Simple Harmonic Motion)
An oscillation in which the acceleration of an object is directly proportional to its displacement from the midpoint, and is directed towards the midpoint
Resonance
When the driving frequency is equal to the natural frequency
(the system gains energy from the driving force and vibrates with a rapidly increasing amplitude)
Damping
Reduces the amplitude if the oscillation over time. The heavier the damping, the quicker the amplitude is reduced to zero.
Gravitational field lines
Arrows showing the direction of the force that masses would feel in a gravitational field
Gravitational field strength
The force per unit mass (g)
g=F/m
Satellite
A smaller mass which orbits a much larger mass
Magnetic Field
A region where a force is exerted on magnetic material
Capacitance
The amount of charge stored per volt
Hadrons
Particles that feel the strong interaction (protons and neutrons)
Baryon
Particle with 3 quarks (e.g. protons and neutrons)
Meson
Particle with 1 quark and 1 antiquark
(E.g. Pions and Kaons)
-unstable
