Class19

Class19 - Technologies Based on Interactions of Matter with...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Technologies Based on Interactions of Matter with Electromagnetic Radiation (EMR) Technologies that provide for the wants of humans: quality and
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Tro, 162 Electromagnetic radiation (emr) is energy moving through space in a wave motion Visible (Vis)
Background image of page 2
How does EMR interact with matter? When emr strikes matter, energy may be transferred to the molecules making up the matter Energies of molecules are quantized, i.e., can only have certain values called energy levels If the amount of energy absorbed is sufficient to change the energy level of the molecule, the added energy causes changes in some kind(s) of motions associated with the molecule If the amount of energy absorbed is insufficient to change the energy level of the molecule, the molecule does not undergo any changes and is said to be transparent to that radiation
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Ground state is energy at “room conditions” Excited states correspond to higher energies resulting from adding (red arrow) specific amounts of energy to the ground state Amount of energy added must equal the difference between the energies of the initial and final states Following exposure to emr, molecules emit specific energies (blue arrows) and tend to return to ground state by all possible paths Energy Level Diagram Energy Absorpti on of energy Emission of energy 1 2 3 4 5 Ground state Excited states Quantized - can only have certain values - not continuous (Ground state) Excited states
Background image of page 4
http://www.easymeasure.co.uk/webs/3/html/510/fig1.gif Nucleus of H atom is spinning and functions as a weak magnet. Science basis for using radiowaves in technologies
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Radiowaves change alignment of nuclear magnets with an external magnetic field *Resonance frequency is the frequency of the radiowave that causes change in the orientation of the nuclear magnet. Depends on strength of external magnetic field. External magnetic field
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 33

Class19 - Technologies Based on Interactions of Matter with...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online