Radioactivity - PowerPoint PPT Presentation

Loading...

PPT – Radioactivity PowerPoint presentation | free to download - id: 77c08b-ZTY4N



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Radioactivity

Description:

Radioactivity When and How was Radioactivity Discovered? 1896 Becquerel left uranium salt on a photographic plate and it made an image He thought that it must of ... – PowerPoint PPT presentation

Number of Views:83
Avg rating:3.0/5.0
Slides: 18
Provided by: Anast72
Learn more at: http://reid.academyatcentral.com
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Radioactivity


1
Radioactivity
2
When and How was Radioactivity Discovered?
  • 1896 Becquerel left uranium salt on a
    photographic plate and it made an image
  • He thought that it must of emitted some invisible
    rays
  • Marie Curie discovered that this was true of
    other elements
  • Of course these guys died rather quickly.

3
Which elements are prone to decay?
  • Large nuclei ( more than 83 protons) tend to
    decay
  • We call these elements RADIOACTIVE
  • When they decay they TRANSMUTATE (change) into
    another Element.

4
Alpha Decay
  • An alpha particle has two protons and two
    neutrons.
  • It is written as 42He
  • 4 is the mass and 2 is the proton number.
  • What happens after alpha decay?

5
(No Transcript)
6
Beta Decay
  • During beta decay a neutron breaks down into a
    proton.
  • This then causes an electron to be lost
  • This is written as -10e

7
(No Transcript)
8
What are gamma rays?
  • This the release energy only and so it has no
    mass and no charge.
  • It is the most penetrating and dangerous kind of
    radiation .

9
What is the order of danger for radiation?
  • Alpha ? Beta ? Gamma
  • Alpha radiation is the least dangers and Gamma
    is the most dangerous.
  • Alpha radiation can be stopped by a sheet of
    paper.

10
How long does decay take?
  • If an element is radioactive then it decays at a
    certain rate.
  • For some it is less then a second and for some it
    is millions of years.
  • The amount of time required for half a substance
    to decay is called the HALF-LIFE
  • What is left is the DAUGHTER NUCLEUS

11
Uses of radioactive decay
  1. Carbon dating - a measure of decay of carbon
    from C-14 to C-12
  2. Uranium dating used to measure the age of
    rocks.

12
How do we detect Radioactivity?
  1. Cloud chamber
  2. Bubble chamber
  3. Electroscope
  4. Geiger Counter

13
Nuclear Fission
  • It was discovered that nuclei can sometimes
    absorb NEUTRONS.
  • This absorption most often caused the nucleus to
    split apart
  • THIS IS CALLED FISSION
  • This is only possible with large radioactive
    nuclei.

14
Chain Reactions
  • The released neutron is capable of hitting other
    nuclei and causing a chain reaction.

15
Nuclear Fusion
  • This is a rare process where two nuclei of low
    mass actually COMBINE.
  • Requirements
  • Low mass nuclei ( hydrogen )
  • EXTREMELY HIGH TEMP
  • Only happens in the SUN ( stars)

16
Fusion Picture
17
Uses of Nuclear Reactions
  • Tracers can track a particle by using
    radioisotopes for diagnosis
  • Treatment of Cancer
  • Nuclear Power Plants
  • 4. Weaponry
About PowerShow.com