he l NS ped us IDE understand AN ATOM
Qu ph a ys
m u ts t n is ic
In the 1920s, physicists realized that tiny particles inside atoms do not behave according to Newton’s laws of motion. Here are some scientists who made leaps in this mind-bending field of science called quantum physics.
ho I w rs orld e e n o i w The p t he
James Chadwick Chadwick worked with nuclear physicist Ernest Rutherford in various radioactivity studies. By 1920, physicists understood that most of an atom’s mass lay in its central nucleus, which contained protons (particles with a positive electric charge). In 1932, Chadwick confirmed that an atom’s nucleus also contained uncharged particles, which he named NEUTRONS. This discovery won him the 1935 Nobel Prize in Physics.
Werner Heisenberg Awarded the Nobel Prize in Physics in 1932, this German-born physicist is best known for developing the UNCERTAINTY PRINCIPLE. This tells us that unlike Newton’s Universe – in which things run according to firm laws – there is only so much we can know about how tiny particles behave inside atoms. You can know where a particle is, or how fast it is moving, but can’t know both things. Their random behaviour can only be predicted on the basis of probability. 96
? nowwas k youhadwick war d i D es C er of ing Jam prison ny dur . a erma ar I in G orld W W
