Radioactivity Flashcards
(13 cards)
What is an ion?
An atom or molecule with a total positive or negative charge
What is an isotope?
Atoms of the same element with a different number of neutrons
What is an alpha particle?
A particle consisting of 2 protons and 2 neutrons, emitted from an unstable nucleus
When given off the mass number decreases by 4 and the atomic number decreases by 2
What is a beta particle?
A particle consisting of an electron emitted when a neutron in the nucleus turns into a proton
The mass number stays the same but the atomic number increases by 1
What are gamma rays?
High energy, high frequency waves
The energy is emitted and the mass and atomic numbers stay the same
What is ionisation?
When electrons are knocked out of an atom making them charged
Why is nuclear radiation dangerous?
If living cells become ionised then one of three things happens:
• the cell dies
• the cell repairs itself
• the cell mutates incorrectly and can become cancerous
What is gamma radiation a form of?
Electromagnetic radiation
What is a half-life?
The average time it takes for half of the nuclei present in a radioisotope to decay
What is irradiation?
When objects that are near a radioactive source are irradiated by it, but this doesn’t make the object radioactive
How can radioactivity be used?
• Radiotherapy:
- cancer treatment
- control/kill cancer cells
• Smoke alarms (alpha)
• Detecting underground leaks (gamma)
• Carbon dating (living wood containing radioactive carbon with a half-life if 5600 years)
• Uranium dating (finding the age of igneous rock)
What is nuclear fusion?
The joining of 2 nuclei to form a larger one
The nuclei collide and fuse together, emitting energy
What is nuclear fission?
The splitting of atoms
A neutron is fried at a large nucleus
The unstable isotope splits releasing energy and high speed neutrons
