Bequerel 1899

Contact print of U

Containing rock

Becquerel’s experiment

Radioactivity

• Discovery

• Types of radioactivity

• Measuring radioactivity

• ½ lives• ½ lives

• Effects

• uses

Ionizing radiation

• Energy enough to knock e- off atoms or

molecules

waves

Vibration of electrical/magnetic field (perpendicular)

(remember feeling the interaction of the fields with the Tesla

Coil and magnet??)

UVbeads

Radioactive decay

• Alpha α

235U

Large nuclei –

Usually above Bismuth

All elements after Bi

Are radioactive (unstable)

Alpha decay examples

• Am 241

• Pu 239

• Ra 222

Alpha decay examples

• Am 241

• Pu 239

• Ra 222

Beta decay

• Beta minus decay

• Nucleus loses an electron…..???

Beta-plus

F-19(PET scans)

Positron + electron� energy

Gamma decay

99Tc

Gamma camera image

Of container truck

summary

Pg 327

Symbols for nuclear “particles”

•0

-1e electron, β−

•0

+1e positron

•4 He, α alpha

00γ gamma

10n neutron

•4

2He, α alpha11p proton

Pg 320

What pieces are missing – add the atomic numbers and determine the missing piece

Transmutation, fission, fusion, alpha, beta-, beta+, gamma,

electron capture