Chapter 11 Radioactive Elements

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Chapter 11 Radioactive Elements Powered By Docstoc
					      Fundamental Atom Forces
1.   gravity-
        • ____________ of the 4 forces
        • Exerted by _________ objects in the universe
        • It is the force of _____________ between objects
2.   Electromagnetic-
        • Second strongest of the 4 forces
        • The force that keeps atoms ______________.
        • Deals with attraction and repulsion so it also deals with
            positive and negative charges.
3.   Strong Nuclear Force-
        • Strongest of the 4 forces
        • The force that holds quarks together inside protons and
            neutrons and keeps the protons and neutrons
            ____________ the nucleus.
4.   Weak Nuclear Force-
        • The force responsible for ____________ decay.
        • Least familiar of the 4 forces
           Wilhem Roentgen
• Discovered x-rays which lead other
  scientists to discover radioactive particles or
     Chapter 11
Radioactive Elements
              Henri Becquerel
          •   Born Dec. 15, 1852
          •   Discovered
              _________in 1896
          •   Awarded
              NoblePrize in 1903
          •   Died Aug. 25, 1908
           Chapter 11
      Radioactive Elements
History behind Nuclear Radiation:
1. The “Father of Nuclear Radiation”
  was Henri Becquerel (1800’s).
    A) Was the 1st to research
    nuclear radiation.
    B) Discovered the first
    radioactive element, __________.
2. Other leaders in the field of
nuclear radiation research included
Pierre and Marie Curie.
   A) Discovered 2 other
   radioactive elements,
____________ and ___________.
What makes an atom radioactive?

• A _________ nuclear
  force! This creates an
  _______ nucleus.
1. Radioactivity- ________ that is emitted
  from radioactive elements in the form of
  _________ or a _______.
2. Types of Radiation (3 kinds)-
     A) Alpha Particles- 1 _______ particle
     released from an element gives off 2
  protons and 2 neutrons.
           * have an overall ______ charge
           * _________ form of radiation
   B) Beta Particles- 1 _______ particle is
    made by the breakdown of neutrons in
the _________ to make an electron inside
the nucleus.
    * more penetrating than alpha
    C) Gamma Rays- They are a form
    of electromagnetic energy or wave.
    * have hi frequencies and have the
    ________ energy.
Radioactive Decay:
1. Radioactive Decay- when unstable
  nuclei of atoms OR isotopes of atoms
  undergo nuclear reactions to become
  ________. THIS FORMS A ______
  ELEMENT! (called transmutation)
    A) Parent Material- starting element
    B) Daughter Material- ending element
2. Types of Decay-
  A) Alpha Decay-
     * nucleus releases an _________
  ________ (2 P and 2 N)
     * reduces atomic # by _____
     * reduces mass # by ______
  B) Beta Decay-
      * releases a ________ ________ (1e-
  released from the nucleus)
      * increases atomic number by_______
      * mass # does ________ change
C) Gamma Decay-
      * emits a gamma ray
      * _________ does NOT change
Decay Series- the step by step process by
 which a radioactive element ________.

Half Life- the time it takes for _____
 of the atoms in an _______ to
Nuclear Fission and Fusion:
1. Nuclear Fission- occurs when an
  atom’s nucleus is ________ into 2
  _______ nuclei with about the
  same mass.
     A) To occur, an atom’s nucleus
     is hit with with a neutron
B) The products are 2 new
nuclei and 2-3 neutrons
     Ex.) U-235
C) 1 split does not give off a
large amount of energy. BUT, a
chain reaction occurs (a series
of fission reactions). This
___________ a lot of energy.
     Ex.) atomic bomb
2. Nuclear Fusion- Occurs when 2 nuclei
 with small masses _______to form a
 nucleus with a large mass.
     A) It’s a thermonuclear
     B) Hard to reach temperatures
     for fusion on Earth, but happens
     naturally on the ________.
Ex.) H-bomb
C) Advantages of Fusion over
* Releases ______ energy
* produces ______ radioactive
* Fuels (water components) needed
to start a fusion reaction are in
     D) Disadvantages of Fusion-
     * Hard to start, control, and
     sustain these reactions.
     * Hard to reach the needed

Detecting Radioactivity:
There are several ways to detect radioactivity.
 Two of the most common are the
 electroscope and the Geiger counter.

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