CH 301 Lecture Notes - Lecture 5: Electric Arc, Flame Test, Room Temperature
Document Summary
Wavelength: measure of distance covered by the wave. Frequency: number of waves that pass a point in a given time. Electric and magnetic fields that are always perpendicular. As wavelengths get shorter, the frequency gets higher. Gamma x-rays ultraviolet infrared microwave radio waves. Experiments where matter gives off light: flame tests. Different colors for different metals (fireworks: electrical discharges in gases. Neon gas under low pressure excited by an electric arc: blackbody radiation. Heating a bar of iron to red heat than hotter to white hot. Radiation emitted light given out as electron returns to atom. Radiation emitted by an opaque or non-reflective body. Spectrum and intensity depend only on temperature of body. Room temperature radiation given off is in the infra-red (non-visible to us) It moves from the visible to the ultraviolet region. With increasing temperature (from low to high temp): dull red more orange more white bluish white. Radiation curves depend only on the temperature of the body!!
