What is radioactivity?
What is Radioactivity?
Radioactivity
-unstable nuclei
-emitting particles or releasing energy
What is nuclear decay?
Nuclear Decay
-atom changes into isotope of same element or a new element
What is nuclear radiation?
Nuclear Radiation
-can damage living tissue
-released energy or matter
What types of nuclear radiation are
there?
Types of Nuclear Radiation
-alpha particles
-beta particles
-gamma rays
-neutron emission
Radioactivity occurs when unstable nuclei release energy or particles. Nuclear radiation can
damage living tissue. There are 4 types of nuclear radiation: alpha particle, beta particle, gamma
rays, and neutron emission.
What are alpha particles?
What is Radioactivity?
Alpha Particles
-two protons and two neutrons
-positive charge (+2)
-most massive
-do not travel far through materials
-large size and ionizing matter slows A.P. down
What are beta particles?
Beta Particles
-negative charge (-1)
-faster than A.P.
-travels farther into matter than A.P.
-neutron decays into a proton and an electron
-electron ejected
-lose speed as they ionize matter
What are gamma rays?
Gamma Rays
-penetrates matter more than B.P.
-not made of matter
-no charge
-electromagnetic energy
-do not ionize matter
-greater danger than A.P. and B.P.
What are neutron emissions?
Neutron Emission
-neutron emitted from unstable nuclei
-no charge
-does not ionize matter
-travels further into matter than A.P or B.P.
Alpha particles consist of two protons and two neutrons. They are positively charged (+2). They
are the most massive radioactive particle. Beta particles are negatively charged electrons formed
from a neutron decaying. Gamma rays are a form of electromagnetic energy with no charge.
Neutron emission occurs when a neutron is emitted from an unstable nucleus.
What is Radioactivity?
What is a half-life?
Half-life
-time it takes ½ of a radioactive substance to decay
What determines half-life?
-different radioactive isotopes have different half-lives
-depends on nucleus stability
Radioactive substances decay at a rate known as a half-life. This is the time needed for half of a
radioactive substance to decay. The rate of decay depends on the stability of the nucleus.