chapter 22 - radioacitivity Flashcards
atomic number
number of protons in an atom
atomic number
number of protons and neutron in an atom
isotopes
atoms of the element with the same number of protons but a different number of neutrons
ionization
process were electrical neutral atoms or molecules are converted to electrically charged atoms or molecule through gaining or losing electrons
random
it is impossible to predict exactly which nucleus and exactly when a particular nucleus will disintegrate
spontaneous
takes place by itself without any external influence
background radiation
nuclear radiation in an environment where no radiation source has been deliberately introduced (rocks in the ground, bricks, nuclear waste from power stations)
half-life
the time taken for half the nuclei of the nuclide in any sample to decay
alpha decay
atom → daughter nucleus (nucleon no. decrease by 4 + atomic number decrease by 2) + helium atom
beta decay
atom → daughter nucleus (atom no. increase by one) + electron (0 nucleon number + -1 atomic no.)
gamma decay
(atom)* → (atom) + γ
nuclear fission
process in which nucleus of atom splits (usually into two parts) and releases a huge amount of energy
nuclear fusion
process in which two light atomic nuclei combine to form one heavier atomic nucleus and release a large amount of energy
nature, mass, charge, speed, ionizing power, penetrating power and effect of electric field by alpha particles
- nucleus of helium atom
- heavy
- positive
- 10% speed of light
- strong
- easily stopped by piece of paper, thin aluminium foil, or human skin
- deflection towards negative plate
nature, mass, charge, speed, ionizing power, penetrating power and effect of electric field by beta particles
- fast moving electron ejected from a radioactive nucleus
- light
- negative
- 80% speed of light
- moderate
- stopped by piece of aluminium
- deflection towards positive plate
