nuclear chemistry n.
Download
Skip this Video
Download Presentation
Nuclear Chemistry

Loading in 2 Seconds...

play fullscreen
1 / 50

Nuclear Chemistry - PowerPoint PPT Presentation


  • 61 Views
  • Uploaded on

Nuclear Chemistry. CHAPTER 10. Intro Clip (2:40). 10.1 Radioactivity. Radioactivity - when an unstable atomic nucleus emits charged particles and energy. Nuclear decay - atoms of 1 element can change into atoms of a different element.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Nuclear Chemistry' - moses-barnett


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
nuclear chemistry

Nuclear Chemistry

CHAPTER 10

Intro Clip (2:40)

10 1 radioactivity
10.1 Radioactivity
  • Radioactivity - when an unstable atomic nucleus emits charged particles and energy.
  • Nuclear decay - atoms of 1 element can change into atoms of a different element.
over100 mammoths died at a sinkhole in hot springs south dakota
Over100 mammoths died at a sinkhole in Hot Springs, South Dakota.
  • Can you determine a way to calculate how old these once furry elephants might be?
carbon 14 dating
Carbon-14 Dating

They are about 26,000 years old.

Mammoth Tooth

FYI: Ms. Lolich went here on a quick trip west.

Yes…….she is a science geek.

nuclear radiation
Nuclear radiation
  • Charged particles & energy that are emitted from the nuclei of radioisotopes.
    • Alpha
    • Beta
    • Gamma
alpha decay
Alpha Decay
  • positively charged (+2)
  • 2 protons and 2 neutrons (like He but no e)
  • symbol 42He or the Greek letter α.
  • Low penetrating power
  • Travel only a few cm. thru air.
  • Does not pose a health hazard
what do those numbers mean
What do those numbers mean?

Mass Number

Atomic Number

example of alpha decay
Example of Alpha Decay

24094 Pu 23692 U + 42 He

beta decay
Beta Decay
  • Occurs when a neutron decomposes into a proton and an electron.
  • negative charge
  • no mass
  • symbol 0−1e or the Greek letter β.
  • 100x more penetrating than the α particle.
  • Can pass through clothing and damage skin.
  • * assigned an atomic number of −1
example of beta decay
Example of Beta Decay

22888 Ra 22889 Ac + 0-1e

gamma decay
Gamma Decay
  • Energetic form of light similar to X-ray
  • Has no mass - does not affect atomic # or mass # (like an electron)
  • Often occurs with α and β radiation
  • no charge
  • Greek symbol is γ
  • Can travel through tissue and solid material - stopped by concrete and lead.
example of gamma decay
Example of Gamma Decay

24094 Pu 24094 Pu + γ radiation

effects of nuclear radiation
Effects of Nuclear Radiation

Background radiation - naturally occurs in the environment.

1. You’re exposed daily.

2. Found in: air, water, rocks, plants, and animals, comic rays.

3. Not harmful.

effects of nuclear radiation1
Effects of Nuclear Radiation

Once nuclear radiation exceeds background levels, it can damage the cells and tissues of your body.

David Hahn needs Proactive – NOT!

detecting nuclear radiation
Detecting Nuclear Radiation
  • Devices that are used to detect nuclear radiation include:
    • Geiger counters
    • Film badges.
10 2 rates of nuclear decay
10.2 Rates of Nuclear Decay
  • A half-life is the time required for one half of a sample of a radioisotope to decay.

Video Clip (1:24)

so how long does it take anyhow
So how long does it take anyhow?
  • Half-lives can vary
    • fractions of a second
    • billions of years.
  • Nuclear decay rates are constant.
after one half life 8 07 days half of a sample of iodine 131 will have decayed into xenon 131
After one half-life (8.07 days), half of a sample of iodine-131 will have decayed into xenon-131.
lab to follow
Lab to follow
  • Calculating Half-Life of BariumStudents will observe radioactive decay and collect data from their Geiger counter to graph the half-life decay process.
10 3 artificial transmutation
10.3 Artificial Transmutation
  • Transmutation - conversion of atoms of 1 element to atoms of another.
  • Involves a nuclear change, NOT a chemical change.

Video Clip (2:04)

natural all the way
Natural all the way
  • In natural transmutations, the nucleus decays spontaneously.
  • There is only 1 reactant (or the nucleus) that undergoes the transformation.
  • Alpha or beta particles are emitted.
so how do they do it artificially
So how do they do it artificially?
  • Scientists bombard the atomic nuclei with high-energy particles such as protons, neutrons, or alpha particles.
  • Particles are accelerated in accelerators, by using electric and magnetic fields.
way to go ernie
Way to go Ernie!!
  • In 1919, Ernest Rutherford bombarded nitrogen-14 with α particles.
  • Notice the left side balanced with right.
10 4 fission and fusion
10.4 Fission and Fusion
  • P4.12d
  • Identify the source of energy in fission and fusion nuclear reactions.

Video Clip (FIRST 1:06 )

so what is nuclear force
So what isnuclear force?
  • Binds protons and neutrons together in the nucleus.
  • Over very short distances its greater than the electric forces.

Remember + and + repel but NOT with nuclear force!!

fission
Fission
  • The splitting of an atomic nucleus into two smaller parts.
  • Tremendous amounts of energy are produced from very small amounts of mass.
  • This is how our nuclear reactor plants work.
did you know
Did you know?
  • 1 kilogram of uranium-235 is equal to the chemical energy produced by burning more than 17,000 kilograms of coal!
what ms lolich sees in her head
What Ms. Lolich sees in her head

FISSION

ISSIO

SCISSORS

ISSO

So Fission is like Scissors – right?

fusion
Fusion
  • When the nuclei of 2 atoms

combine to form a larger nucleus.

  • Fusion also has a small fraction of the reactant mass that is converted into energy.
  • This is how our sun works and reactor made in Junkyard Science article.
what do you need you ask
What do you need you ask?
  • High temperatures.
  • Plasma must exist.
  • Plasma is a state of matter in which atoms have been stripped of their electrons.

Think of plasma (gas) = nuclei & electrons

let s break it down
Let’s break it down….

…More like “stick it” together.