Review for Test

Electromagnetic Spectrum

&

Nuclear Chemistry

Electromagnetic Spectrum

• Understand that the longer the wavelength, the shorter the frequency (inversely proportional). The greater the frequency, the higher the energy (directly proportional) (see the diagrams you were given)

• Rank EM radiation in decreasing or increasing order of wavelength, frequency, and/or energy (see diagrams handed out)

Calculations• Be able to manipulate the following equations to solve for various

variables

c = λv where c = speed of light

3.00 x 108 m/s

λ is wavelength (m)

v = frequency (hz or 1/s)

E = hv where h = 6.626 x 10-34 J s

E = energy (J)

v = frequency (hz or 1/s)

E = hc

λ

Summary

• Nuclear Radiation can be naturally occurring or man-made• Most of radiation we are exposed to is naturally

occurring – alpha rays• Alpha Radiation – weakest (blocked by skin, paper, or cloth)• Beta Radiation – medium (blocked by wood or foil)• Gamma Radiation – strongest (blocked by lead or concrete)

*See graphic organizer / table• Key Nuclear Science Pioneers – Henri Beckerel, Marie and

Pierre Curie

Summary

• How to Write Nuclear Notation

• Symbols for:Beta Particles Alpha Particles

Positrons Neutrons

Gamma Rays γ

Atomic Mass

Atomic No. Element symbol

1n0

Summary• Balancing Nuclear Equations (Law

of Conservation of Mass)

• Coefficients can only be added in front of nuclear particles (alpha particles, beta particles, positrons, neutrons, gamma particles)

SUMMARY - Half-Life Calculations• How to calculate number of half-lives (1/2 x ½ x…) or

1/amount remaining (as decimal or fraction) = 2n where n = no. half-lives

remember percent remaining = 100 – percent decayed

• How to calculate how old something is (no. of half-lives x time per half-life)

• Calculate amount remaining (A) after a certain number of half-lives

A = Ao (where Ao = original amount)

2n (where n = no. of half-lives)• Calculate percentage remaining

__1_x 100%

2n (where n = no. of half-lives)

Summary– Describe the difference between:– fission (splitting atoms)

• 3 steps – Initiation– Propagation– Production of large amounts of energy

– fusion (combining nuclei)– Describe the pros and cons of fission and fusion– Identify examples

– Examples of beneficial and harmful radiation sources• Power generation• Medical imaging, diagnostics, disease treatments• Food safety• Other – historical dating, smoke detectors, etc.

– Know what percentage of US and world energy comes from nuclear material. Know

the country that leads in nuclear usage.