physics Flashcards
The 2 units of activity
joules
Becquerel
what happens to a nucleus that is decaying by neutron emission
mass number stays the same
impossible to predict the amount of ______. It is possible to predict the _______ of a very large number of nuclei after a given amount of time using _____
decay, activity, half life
what happens to the mass and charge of the nucleus that emits gamma radiation?
nothing happens, its a wave
Gamma emitting particles are injected into patients’ bloodstream and detected, why use gamma rays?
Gamma rays are used as it has high penetration but weak ionisation
Man made sources of radiation, 4 of them
Xray
fallout from nuclear weapons testing
the fallout from nuclear testing
nuclear power
Natural sources of radiation, 4 of them
rocks
animals
plants
gamma rays
an instrument used to test for radiation
Geiger muller tube
or cloud chamber
two factors that can affect the levels of a background radiation test
- how close you are to the atom
- altitude or latitude
why does a student that lives near plenty of houses not have to be worried about background radiation?
there are no nuclear power stations nearby
radioactive decay is a ________
systematic process
Alpha radiation =
helium nuclei
Beta radiation =
high energy electrons
Gamma radiation =
electromagnetic waves
Alpha radiations range, power, and penetration
3.5cm in air, strongest ionising, low penetration
Beta, range, power, penetration
15cm in air, medium ionising, medium penetration
Gamma, range power penetration
longest range weakest ionising strongest penetration
Half-life meaning
Half the radioactive atoms decay
irradation
extract 1
contamination
extract 2
what can exposure to ionizing radiation lead to
can lead to tumors, cancers and the blood cells becoming ionised
protection for radation
gloves and a protective suit
the half-life of this radioactive isotope?
2
how rutherfords experiments disproved the plum model
rutherford shot a beam of alpha particles at a thin sheet of gold foil, he found that most went through meaning there is empty space, however, some were deflected meaning there is a positively charged nucleus.
This disproves the plum pudding model as its a ball of positive charge dotted with negative charge.
rutherfords experiment and how it changed the current atom model
a quick recap of rutherfords experiment:
he fired a beam of alpha particles at a thin sheet of gold foil, most went through meaning there is empty space, however, some were deflected, meaning there is a positively charged nucleus
lead to the current atom model consisting of a positive nucleus
