AST101H1 Chapter Notes - Chapter 5: Electromagnetic Spectrum, Mass Number, Electric Charge

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Ian Shelton

Document Summary

Chapter 5: light and matter; reading messages from the cosmos. The rate of energy flow is called power, which we measure in units called watts a power of 1 watt means an energy flow of 1 joule per second: 1 watt = 1 joule/s. When we pass white light through a prism, it disperses into a rainbow of colour that we call a spectrum the basic colours in a rainbowlike spectrum are red, orange, yellow, green, blue and violet. We see white when the basic colours are mixed in roughly equal proportions light from the sun, or a light bulb is often called white light, because it contains all the colours of the rainbow. Black is what we perceive where there is no light and hence no colour. Emission: a light bulb emits visible light; the energy of the light comes from electrical potential energy supplied to the light bulb.