Radioactivity Flashcards
Isotopes
Atoms from the same element that differ the amount of neutron in the nucleus
Stable
When a nucleus does not change spontaneously. The protons and neutrons are held strongly together.
Un stable
When a nucleus does change spontaneously. The protons and neutrons are not held strongly together.
Radiostopes
A form of an unstable isotope
Nuclear radiation
Radiation from the nucleus. It contains both alpha and beta particles.
Alpha particles
Positive parts of helium atoms containing 2 protons and 2 neutrons.
Nuclear Radiation
Nucleus of a radioactive atoms. fast moving particles emitted by the nucleus
Are alpha particles dangerous?
They are only dangerous when the source is inside your body
Alpha particles
Helium nucleus
2 protons
2 neutrons no electrons
Stopped by a sheet of paper or human skin
Helium
Helium has a charge a positive 2 be cause it has 2 protons and no electrons
How fast is alpha
It is 5- 10 % the speed of light = 15000000m/s
Beta
Proton+electron when an electron is released they travel between 50 and 70% of the speed of light. They can pass through dead skin but not a thin sheet of aluminium, plastic or wood. 99% of the speed of light.
Gamma rays
Gamma rays are high energy electromagnetic radiation that are produced during nuclear reactions. They have no mass and travel at the speed of light. Shielded by thick sheets of lead or concrete.
Half life
the time taken for the radioactivity of a specified isotope to fall to half its original mass.
Cosmic radiation
Cosmic rays are atom fragments that rain down on the Earth from outside of the solar system. They blaze at the speed of light.
