raidioactivity Flashcards
(32 cards)
Why do some nuclei emit radiation?
because they are unstable due to having an imbalance of protons or neutrons.
What are the three types of radiation that a nucleus can emit
alpha
beta
gamma
What is an alpha particle?
An alpha particle is composed of two protons and two neutrons. It is equivalent to a helium nucleus
What is gamma radiation?
Gamma radiation is a type of high-energy electromagnetic wave
True or False?
Alpha particles have a charge of -1.
False.
Alpha particles have a charge of +2 due to having two positively charged protons
Which type of nuclear radiation is the most ionising?
Alpha
Which types of nuclear decay cause the isotope to decay into a new element?
alpha and beta decay will produce a new element.
By what value does the mass number decrease as a result of alpha decay?
Alpha decay results in the mass number decreasing by 4, because 4 nucleons are emitted
True or False?
In beta decay, a neutron changes into a proton and an electron
True.
A neutron changes into a proton and an electron during beta decay.
By what value does the atomic number decrease as a result of alpha decay?
2
How are the mass and atomic numbers affected by gamma decay
Gamma decay has no effect on the mass number or the atomic number
By what value does the atomic number change as a result of beta decay?
The atomic number increases by 1 as a result of beta decay
By what value does the charge on a nucleus decrease when it emits an alpha particle
The charge on a nucleus will decrease by 2
By what value does the mass number decrease as a result of beta decay
The mass number remains unchanged by beta decay
Name two methods of detecting ionising radiation
photographic film
a Geiger-Muller tube / counter
Define background radiation
Background radiation is the radiation that exists around us all the time
What are natural sources of background radiation (3)
radon gas
cosmic rays from space
radioactive elements in rocks and soil
What are the units of count rate
Count rate is measured in counts per second or counts per minute
how does the does the count rate change as the detector moves further away from a source of radiation
The count rate decreases as the detector moves further from the radiation source.
What is a becquerel
the unit for raidioactivity
What is the difference between activity and count rate
Activity is the rate at which radiation is emitted, whereas count rate is the rate at which radiation is detected
Define the term half-life.
Half-life is the time taken for half the nuclei of a particular isotope in any sample to decay
Which type of nuclear radiation is used for measuring and controlling the thickness of materials?
Beta
Which type of nuclear radiation is used for irradiating food to kill bacteria
Gamma
