Nuclear Radiation > Nuclear Radiation & Transformations

Nuclear Radiation > Marie Curie  Marie Curie was a Polish scientist whose research led to many discoveries about radiation and radioactive elements. In 1934 she died from leukemia caused by her long-term exposure to radiation.

Nuclear Radiation > Radioactivity  Marie Curie ( ) and Pierre Curie ( ) were able to show that rays emitted by uranium atoms caused fogging in photographic plates.  Marie Curie named the process by which materials give off such rays radioactivity.  The penetrating rays and particles emitted by a radioactive source are called radiation.

Nuclear Radiation > Radioactivity  In nuclear reactions, the nuclei of unstable isotopes, called radioisotopes, gain stability by undergoing changes.  An unstable nucleus releases energy by emitting radiation during the process of radioactive decay.

Nuclear Radiation > Types of Radiation  Alpha  Beta  Gamma

Nuclear Radiation > Alpha Radiation  Nuclear Symbol:  Made of:  Mass:  Charge: 2 p + and 2 n He 2 4 α 2 4 or

Nuclear Radiation > Alpha Decay

Nuclear Radiation > Beta Radiation  An electron resulting from the breaking apart of a neutron in an atom is called a beta particle.

Nuclear Radiation > Beta Radiation  Nuclear Symbol:  Made of:  Mass:  Charge: e 0 orβ 0 electrons (-) 0

Nuclear Radiation > Beta Decay

Nuclear Radiation > Gamma Radiation -Usually emitted along with alpha radiation or beta radiation.  Nuclear Symbol:  Made of:  Mass:  Charge: γ electromagnetic waves 0 0

Nuclear Radiation > Gamma-Ray Radiation Cobalt-60 Nickel-60

Nuclear Radiation > What stops alpha, beta, and gamma radiation? Alpha particles are the least penetrating. Gamma rays are the most penetrating.

Nuclear Radiation > Nuclear Stability and Decay  The stability of the nucleus determines the type of decay (alpha, beta, gamma) a radioisotope undergoes.  The protons in a nucleus want to repel against each other.  There is a strong force that holds the protons and neutrons together in the nucleus

Nuclear Radiation > What makes an atom radioactive?  When the strong nuclear force cannot hold the protons and neutrons together.

Nuclear Radiation > Which elements are unstable (radioactive)?  All nuclei with more than 83 protons (shade these in on the small periodic table)  However, many other nuclei with only a few protons are also radioactive

Nuclear Radiation > Transmutation Reactions  The conversion of an atom of one element to an atom of another element is called transmutation.  Transmutation can occur by radioactive decay.  Transmutation can also occur when particles bombard the nucleus of an atom.

Nuclear Radiation > Fission & Fusion BOTH: release A LOT of energy

Nuclear Radiation > Fission  A large nucleus is split apart.  Usually releases particles that perpetuate a chain reaction

Nuclear Radiation > Fission

Nuclear Radiation > Fission  A large nucleus is split apart.  Usually releases particles that perpetuate a chain reaction  Used to generate electricity and in nuclear weapons

Nuclear Radiation > Fusion  2 small nuclei combine (fuse together)  Occurs at very high temperature and pressure  Occurs in the sun & other stars

Nuclear Radiation > Fusion

Nuclear Radiation > Geiger Counter  Used to detect radioactive substances

Nuclear Radiation > Effects of Radiation

Nuclear Radiation >

> Half-Life  HALF-LIFE is the time that it takes for 1/2 a sample to decay.  The rate of a nuclear transformation depends only on the “reactant” concentration.

Nuclear Radiation > Half-Life

Nuclear Radiation > Half-Life

Nuclear Radiation > Half-Life  The ratio of Carbon-14 to stable carbon in the remains of an organism changes in a predictable way that enables the archaeologist to obtain an estimate of its age.  Radiocarbon dating is used to determine the approximate age of a sample of matter.