Radioactivity Flashcards Preview

X Physics > Radioactivity > Flashcards

Flashcards in Radioactivity Deck (13):

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