Given this experimental data, Rutherford naturally considered a planetary-model atom, the Rutherford model of 1911 â electrons orbiting a solar nucleus â however, said planetary-model atom has a technical difficulty.
1 Goldâs melting point is at about 1,943 degrees Fahrenheit, which means you will need temperatures that hot to melt it. 2  Thus, it's very important that you don't just choose any container. 3  In addition to a crucible, you will need a pair of tongs to move the crucible and hold it.
Francium, cesium, gallium, and rubidium are four elements that melt at temperatures slightly higher than room temperature. Francium (symbol Fr and atomic number 87), a radioactive and reactive metal, melts around 300 K. Francium is the most electropositive of all the elements.