Electromagnetic Radiation

Question 1

electromagnetic spectrum in order of increasing wavelength

Answer 1

gamma rays, x-rays, ultraviolet, visible light, infrared, microwaves, radiowaves

Question 2

when electromagnetic radiation is absorbed or emitted by matter, what is it in the form of?

Answer 2

a stream of particles called photons, when it is absorbed or emitted energy is gained or lost by electrons within the substance

Question 3

evidence of energy levels in atoms

Answer 3

the spectrum of light emitted consists of a series of lines at discrete frequencies which provides evidence for the existance of discrete energy levels for electrons

Question 4

when does an atom emit a photon of light energy?

Answer 4

when an electron moves from a high energy level to a lower energy level

Question 5

what is atomic emission spectroscopy and atomic absorption spectroscopy used for?

Answer 5

to identify and quantify the elements present in a sample

Question 6

absorption spectroscopy

Answer 6

electromagnetic radiation is directed at an atomised sample and it is absorbed as electrons are promoted to higher energy levels. an absorption spectrum can be produced by measuring how the sample’s transmission of light varies with wavelength

Question 7

emission spectroscopy

Answer 7

high temperatures are used to excite electrons, as they drop to lower energy levels photons are emitted and an emission spectrum can be produced by measuring how much light is emitted at different wavelengths