Term 2 Part 3 - Radiation Flashcards
(28 cards)
what is an isotope?
Atoms of the same element (same number of protons) with different mass numbers/amount of neutrons
what are radioisotopes?
Atoms that have unstable nuclei (eject particles/electromagnetic waves or undergo nuclear decay)
what are 3 factors that make the nucleus unstable?
- Protons can experience electrostatic forces that can make them repel
- A strong nuclear force is needed to keep the protons and neutrons in the nucleus
- Neutrons help to reduce the repulsion between the protons
- Too many neutrons compared to protons
- Nucleus too big
what is radioactivity?
natural decay of unstable nuclei which releases radiation
what is irradiation?
intentional exposure of something to radiation WITHOUT making it radioactive
what is nuclear decay?
Protons and neutrons in the nucleus are constantly moving and rearranging themselves which sometimes causes the nucleus to emit high energy electromagnetic radiation and can cause the article to chnage into a differet element.
what is the relationship between nuclear decay and radiation?
The activity of a radioactive source is the rate at which it decays
what is count rate?
the count rate is the number of decays per second recorded by a detector
what is radioactivity measured with?
radioactivity is measured with a geiger counter
what are the 3 types of radiation?
alpha, beta, gamma
what does an alpha particle contain?
2 protons 2 neutrons
what is an alpha particle emitted from?
Emitted from A NUCLEUS THAT IS TOO BIG
what is the alpha particle symbol?
what does a beta particle contain?
1 electron
what is a beta particle emitted from?
Emitted from A NEUCLEUS WITH TOO MANY NEUTRONS
what does a beta particle split into?
Splits into 1 proton and 1 electron
what is the beta particle symbol?
what is different about gamma from beta and alpha?
it is a ray, not a particle
when are gamma rays emitted?
EMITTED DURING NUCLEAR DECAY
what are 4 properties of alpha particles?
- Strong ionizing power
- because of its 2+ charge it can attract electrons of their electron shells in their atom which can cause the atom to change because the number of electrons changes
- deflects towards NEGATIVELY charged plates/objects
- weakest penetration power
what are 4 properties of beta particles?
- Weaker ionizing power than alpha
- because of its 1- power it needs to come closer the the electron shells in order to REPEL the electron (so the electron leaves the shells but it doesn’t attract towards the beta particles instead it goes the other way because it is repelled)
- deflects towards POSITIVELY charged plates/objects because of its negative charge
- slightly stronger penetration power than alpha
what are 4 properties of gamma rays?
- Weakest ionizing power
- its 0 charge means it has to directly hit the electron in order to knock it off the shells which is rare and hard to do
- undeflected by charged plates/objects because it has no charge
- strongest penetration power
what is the definition of ionising?
particles or waves that cause atoms to lose or gain electrons and become charged
what can alpha, vs beta vs gamma penetrate through?
