Nuclear Chemistry

  • 144 views
Uploaded on

Great overview of nuclear chemistry, including alpha, beta and gamma radiation, fission, fusion and half life calculations.

Great overview of nuclear chemistry, including alpha, beta and gamma radiation, fission, fusion and half life calculations.

More in: Education
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
144
On Slideshare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
14
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Nuclear Chemistry
  • 2. Nuclear Reactions • Nuclear reactions change an atom’s nucleus. • 3 Types of radiation are produced from nuclear reactions: alpha, beta & gamma. –Alpha: positive –Beta: negative –Gamma: no charge
  • 3. • Strong nuclear force: force that holds the protons together in the nucleus • Neutrons add a strong nuclear force to a nucleus, which keeps the protons from breaking the nucleus apart. • All nuclei with atomic numbers >83 are radioactive.
  • 4. • Beyond 20 protons, nuclei need many more neutrons than protons to be stable. • Nuclei can become unstable if there are too many or too few neutrons. • Isotopes that are much heavier or much lighter than the most common isotope are likely to be radioactive.
  • 5. Alpha Particles • An alpha (α) particle has 2 neutrons & 2 protons and is identical to a He-4 nucleus.
  • 6. Beta Particle • a neutron changes into a proton & electron. • The proton stays in the nucleus & the electron/beta particle is propelled out of the nucleus. • Beta particle = electron
  • 7. Gamma Ray • Gamma radiation has no particles. • Most dangerous type of radiation • Emitted from the nuclear bomb
  • 8. Nuclear Fission • When certain elements are struck with neutrons, the nucleus can split into smaller fragments. – Only occurs in Uranium-235 & Plutonium-239 – Creates a chain reaction that releases an immense amount of energy • ~2 lbs of U-235 creates as much energy as 20,000 tons of dynamite – Nuclear bombs use fission – Nuclear Power Plants use fission to heat water
  • 9. Nuclear Fusion • When 2 or more atoms combine to create one atom • Occurs in stars, like our sun – Hydrogen atoms fuse to make helium atoms – When stars run out of hydrogen, they start to die • Creates more energy than fission reactions • Extremely high temperatures are needed to create a fusion reaction – We have not been able to attain temperatures hot enough for us to use nuclear fusion as a power source on Earth
  • 10. Half-Life • Every radioactive sample decays at a certain rate • A half-life is the time required for half of the atoms in the sample to decay into products – Half-lives can range from fractions of a second to billions of years – Half-lives of: • Radon-222: 3.8 days • Carbon-14: 5730 years • Uranium-235: 700,000,000 years
  • 11. Calculating Half-Lives amount _ of _ time _ elapsed length _ of _ halflife number _ of _ halflives • The half-life of Carbon-14 is 5730 years. How many half-lives elapse after 17,190 years? • How many grams of C-14 is left after 3 halflives if it started off with 100 grams? • Starting with 80 grams, how many half-lives have elapsed if you end with 5 grams?
  • 12. • What is the half-life of a 100 g sample of N16 that decays to 12.5 g in 21.6 seconds? • If an 800 g sample of technetium-99 decays to 100 g in 639,000 years, what is its halflife? • A 208 g sample of sodium-24 decays to 13 g of sodium-24 within 60 hours. What is the half-life of this isotope? • The half-life of Au-198 is 2.7 days. How much of a 300g sample will be left after 10.8 days?