physics - chapter 5 (radioactive materials

atomic structure

Positively charged nucleus that contains neutrons and protons, surrounded by negatively charged electrons

radius of atom

1x10^-10

radious of nucleus

10,000 times smaller than atom/ very small

relative mass of electron

very small

relative mass of proton

1

relative mass of neutron

1

relative charge of electron

\-1

relative charge of neutron

0

relative charge of proton

\+1

Dalton - atomic model

* everything made out of tiny spheres
* spheres could not be divided

JJ Thompson

plum pudding model

* discovered the electron
* spheres of positive matter
* tiny negative electrons placed all throughout atom

Rutheford

gold foil experiment

* particles went straight through = lot of empty space in atom
* some particles displaced = nucleus had to be positively charged

alpha

* highly ionising
* weakly penetrating
* helium nucleus

beta

* electron
* medium ionising
* medium penetrating

gamma

* radiation
* low ionising
* highly penetrating

alpha decay

* mass decreases 4
* charge of nucleus decreases 2

beta decay

* mass stays the same
* charge of nucleus will increase 1

gamma decay

* mass stays the same
* charge stays the same

contamination

* lasts long amount of time

irradiation

* lasts for a short period of time
* does NOT make objects radiation

chemotherapy

* gamma rays are emitted
* absorbs the energy of cancerous cells and dies
* hard to direct accurately so healthy cells may be irradiated
* can have unhealthy side effects

smoke alarms

* alpha emitter
* half life of 432 years
* when smoke reaches alarm amount of alpha particles drop
* causing alarm to go
* weak activity so not harmful to anyone