The ancient philosophical spark
Cracking the shell
Mapping the nucleus
The quantum cloud
YOUR GOAL
Master of The story of the atom
testerr Mapping the Nucleus
We shot the gold foil—(bounced right back!) / Who knew the atom was empty space like that?—(space like that!)
testerr James Chadwick discovered the neutron, solving a mystery about the nucleus's weight.
testerr Niels Bohr proposed that electrons orbit the nucleus like planets around the sun.
Empty space: If an atom's nucleus were the size of a marble on a 50-yard line, the entire atom would be the size of a football stadium.
The positively charged central core of an atom, consisting of protons and neutrons and containing nearly all its mass. In 1911, Ernest Rutherford discovered this dense atomic core by firing alpha particles at thin gold foil.
What happens when an electron jumps from a high-energy orbit to a lower-energy orbit in a Bohr atom?
Which Austrian physicist co-discovered nuclear fission in 1938 but was denied the Nobel Prize?
Which Danish physicist proposed in 1913 that electrons orbit the nucleus in fixed paths?
What charged particles make up the positive charge in Rutherford's atomic nucleus?