Radiation and Thermal Energy Our Model of the Atom Evolves
In a chemical reaction, what is happening to the system when there is a change in temperature?
What changes occur in a system when radiating is the transfer mechanism?
Incandescent light bulb • Watch carefully as the power delivered to the light bulb is increased. • Write down your observations.
Incandescent light bulb • Now view the light bulb through a spectrometer as the power delivered to the bulb is increased. • Write down your observations
Compact fluorescent light bulb • Watch carefully as the power delivered to the light bulb is increased. • Write down your observations.
Compact fluorescent light bulb • Now view the light bulb through a spectrometer. • Write down your observations
A hot solid gives a continuous spectrum while a heated gas gives only a piece of the spectrum.
An input of energy is required to make the atoms of an atomic gas emit radiation. • The radiation emitted by each element is unique.
A change in temperature results in a change in structure. • A change in structure results in the emission of light.
In a compound a change in structure can be explained by a rearrangement of the atoms. • How about in atomic gases?
In atomic gases the change in structure has to be at the atomic level.
Our current model of the atom…. • Does not account for these differences in structure, therefore we need a model of the atom with some more internal structure that can account for the radiation emitted by atoms.