1.1 - ER and Atomic Spectra

Question 1

what term is used to describe the characteristic of light behaving as both a wave and a particle

Answer 1

dual nature

Question 2

what does ER behave like when it is absorbed or emitted

Answer 2

a stream of particles called photons

Question 3

what unit is the energy of a mole of photons usually given in

Answer 3

kJmol^-1

Question 4

what provides evidence for the existence of energy levels within an atom

Answer 4

the series of discrete lines across an emission/absorption spectrum, created when light is emitted/absorbed by an atom

Question 5

what allows an emission/absorption spectrum to be used to identify an element

Answer 5

every element produces a characteristic absorption/emission spectrum

Question 6

what allows an emission/absorption spectrum to be used to quantify an element

Answer 6

an absorption/emission spectrum shows the intensity of light absorbed/emitted

Question 7

what does an absorption/emission spectrum show

Answer 7

how the intensity of absorbed/emitted light varies with wavelength/frequency

Question 8

explain absorption spectroscopy

Answer 8

A spectrum of electromagnetic radiation is directed at an atomised sample. Radiation is absorbed at discrete wavelengths as electrons are promoted to higher energy levels.

Question 9

explain emission spectroscopy

Answer 9

high temperatures are used to excite electrons within atoms. As the electrons drop to lower energy levels, photons are emitted.