1. Nuclear Chemistry
A Short Study

3. A Review
Element – Chemical substance that cannot be divided by chemical means
All atoms of the same element have the same atomic number
Atom – A small piece of matter made of a nucleus and electron cloud(s)
Nucleus contains protons and neutrons
Neutral atoms have equal numbers of protons and electrons

4. Review Continued Atomic Number – the number of protons in the nucleus.
Mass Number – The total number of protons and neutrons in the nucleus
Ion – an atom that has lost or gained electrons
Isotopes – atoms of the same element that have different numbers of neutrons

5. The New Stuff
Radiation – energy that is emitted from a source and travels through space
Measured with a Geiger Counter
Have You Ever Been
Exposed to Radiation?
Is all radiation harmful?

6. More Terms
Non-Ionizing Radiation – radiation that does not have enough energy to ionize matter
Ionizing Radiation – High-energy radiation which is capable of knocking electrons out of atoms
Nuclear Radiation – radiation produced from the nucleus of an atom
Radioactive – unstable nucleus which spontaneously emits ionizing radiation

7. Types of Nuclear Radiation
Alpha Particle – (α) helium ions that have no electrons and are positively charged
Beta Particle – (β) electrons emitted at very high speed
Gamma Ray – (γ) high energy radiation which has no mass or charge
Positron – same mass as an electron but with a positive charge

8. Gamma Ray

9. Nuclear Decay Spontaneous Starts as a parent Becomes a daughter
Gives off heat (energy)
May continue as a series until a stable atom is formed
Mass Number and electric charge must be conserved during a nuclear change

10. Band of Stability

11. Types of Decay Alpha Emission Beta Emission
Helium Nucleus is given off
Beta Emission
Electron (β-) or Positron (β+) is given off

12. Decay Terms
Half-life – the time it takes for one-half of the parent to decay
Will the material ever be gone?
What do we do with it?
Some Examples of half-life
Radioactive dating?

13. Fission

14. Nuclear Power Uses fission to generate electricity
Fission = The splitting of a large nucleus to produce smaller ones and energy
Bombardment with neutrons
Need critical mass that will sustain a chain reaction
Controlled in a reactor
Uncontrolled in an explosion
Fusion = The combining of small nuclei to form larger ones releasing energy

15. Fission Reactor

16. Fusion Reactor

17. Synthetic Elements Transmutation – changing one element into another
Carried out in
Nuclear Reactors
Nuclear Explosions
Accelerators
Transuranium – synthetic elements with an atomic number greater than 92