In 1913 Niels Bohr proposed a new model of the atom that included quantized electron orbits: electrons still orbit the nucleus much as planets orbit around the sun, but they are only permitted to inhabit certain orbits, not to orbit at any distance.
About reports the melting point of gold is 1,064.43 degrees Celsius. The melting point of a solid is the temperature at which it becomes a liquid. Gold's boiling point is 2,807 degrees Celsius.
Gallium is a solid metal at room temperature, but it melts in your hands. 00:09. When gallium is in its liquid state, if feels like cold melted solder in your hands. 00:33. Melting gallium onto aluminum makes the aluminum brittle enough to break with your fingers.