Topic 15: Light Emission

Question 1

What are the 2 sources of light emission?

Answer 1

thermal radiation and luminescence

Question 2

Why do all objects emit thermal radiation?

Answer 2

because anything about 0 degrees Kelvin emits some form of electromagnetic radiation and there are no objects is lower than 0 degrees Kelvin

Question 3

What does intensity and wavelength of radiation depend on?

Answer 3

temperature… the higher the temperature, the higher the intensity the lower the wavelength

Question 4

What is luminescence?

Answer 4

light emission caused by the relaxation of electrons, energy corresponds to energy difference between ground state and excited state

Question 5

What is thermal radiation?

Answer 5

energy transfer by emission of electromagnetic waves that carry energy away from the emitting object

Question 6

What is an emission spectrum?

Answer 6

a graph of intensity vs. wavelength showing at which wavelengths an light source emits radiation

Question 7

How can light emission be measured?

Answer 7

spectrometer, spectroscope, flame photometer