1.2 Basic ideas about atoms Flashcards
In terms of an atomic nucleus, what is radioactive decay?
process that takes place when an unstable atomic nucleus loses energy by radiation
what is alpha decay?
A type of radioactive decay where an atomic nucleus loses two protons and two neutrons.
It is a helium nucleus
Atomic number is reduced by two and mass number by four, making the element more stable
what is beta decay?
A type of radioactive decay where a beta particle is lost (an electron). And a neutron turns into a proton or vice versa.
Changes atomic number by one mass number, the same
what is positron emission?
Positron emission is also known as beta decay.
Beta plus particle has the same mass, the opposite charge to an electron
When it’s released, it increases the nucleus’ proton number by one. No effect on mass number.
What is electron capture?
process used by unstable, atoms to make them more stable
An electron is drawn into the nucleus and reacts with the proton to form a neutron.
What is Alpha?
helium nucleus
What is Gamma?
Electromagnetic wave
What is Beta
fast moving electron
What is Ionising Radiation?
Atoms being hit by radiation energetic enough to cause them to become ions (due to electrons being knocked off)
Alphas ionising power
strongly ionising (do to being larger, it is more likely to hit something)
Beta ionising power
moderately ionising
Gamma ionising power
weakly ionising (due to being faster, it is less likely to hit something)
what can alpha be blocked by
paper
what can beta be blocked by
aluminium
what can gamma be blocked by
lead
why are some atomic nuclei unstable
- there is an imbalance between protons and neutrons
- they contain too much energy
why do unstable nuclei give out radiation
- they undergo decay to become more stable
- as they release radiation, their stability increases
what is the name of the process where an unstable nucleus gives out radiation to become more stable
radioactive decay
alpha particle response to a magnetic field
Weakly attracted to the negative magnetic plate
Beta particle response to magnetic field
Strongly attracted to the positive plate
Positron response to magnetic field
Strongly attracted to the negative plate
Gamma radiation response to magnetic field
Not affected by the magnetic field (has no change)