Between 1923 and 1927, Clinton Davisson and Lester Germer experimented with firing accelerated electrons at a crystal of zinc.
a. a Why is Davisson and Germer's experiment, first published in the *Franklin Institute Journal* of 1928, considered to be such an important experiment in the history of physics?
b. b Describe briefly what Davisson and Germer observed and why it was so relevant to de Broglie's hypothesis.