P4.3 Radioactive Emissions Flashcards
What is radioactive decay?
unstable nucleus loses energy by radiation
Is Radioactive decay random?
Yes, we cannot predict when it will happen
What is half life?
Half life is the average time taken for half the amount of the unstable nuclei in a sample to decay
What happens after a nucleus decays?
It could become stable
How is radioactivity of a source measured?
Geiger Muller tube
What do unstable nucleus emit?
Radiation
What does a nucleus become stable mean?
Nucleus emits radiation to become more stable
What does radioactive mean?
Unstable isotopes which can decay. Radiation is the energy or particles that are released during radioactive decay
What does an alpha particle contain?
2 protons
2 neutrons
Same as Helium
Does an alpha particle contain electrons?
No
How good at penetrating is an alpha particle?
Low
How ionising is an alpha particle?
Very
What does an alpha particle do to an electron
Knocks it out its shell
What particle is a beta particle the same as?
Electron
What happens when one of the neutrons decay?
Decays into a proton and electron
What happens to the proton and neutron which have been formed by the neutron in beta decay?
Proton stays in nucleus
Electron is emitted out at high speeds
How ionising and penetrating is beta radiation?
Moderately ionising and penetrating
What is gamma radiation?
Waves of electromagnetic radiation
When is gamma radiation normally emitted?
After, beta and alpha
True or False:
Gamma Rays have no charge or mass
True
How ionising and penetrating are gamma rays?
Ionising - weak
Penetrating - strong
What is neutron emission?
Neutrons being emitted because there are too many, so neutrons are thrown out by nucleus to increase stability
What is ionising radiation?
Removing electrons to form positively charged ions
In nuclear decay does the equation need to be balanced?
Yes
How do you know if its a Beta, Alpha or neutron equation?
n = neutron
2 elements = alpha
e = beta
What does contamination mean?
Radioactive material inside body or on skin, cant be removed
What does irradiation?
Radioactive material outside the body but can travel inside
What is the energy of a photon proportional to?
Frequency
Explain what happens when atoms absorb electromagnetic radiation?
Photons excite electron to higher energy level. When the electron moves from lower to higher energy level its called excited
Can it be any amount of energy to excite the electron?
No, the photon has to have the exact amount of energy
What photons have enough energy to completely remove an electron?
Photons of Ultra-Violet, Xray and Gamma rays.
