All metals are #"malleable"#; and gold is extremely malleable amongst metals. And what does malleable mean? It means that it can be beaten out into a sheet. This property, along with the beauty of gold, makes it a prized material for ornamentation. Sometimes you will see actual gold leaf on decoration....this is real gold, but so thin that you could tear it apart with your fingers, and thus cheap enuff so that it is not terribly expensive to decorate a moulding.
Gold can thus be hammered out into a sheet only a few atoms THICK. When Rutherford fired #alpha-"particles"# (massive helium ions..) at his gold sheet, MOST of the #alpha-"particles"# passed THRU the sheet, as expected; a few were deflected, and fewer still BOUNCED off the gold sheet to direct back towards the #alpha-"particle"# transmitter. This result was entirely unexpected.
Rutherford could only account for these results by proposing a small, dense nuclear core in which ALL of the positive charge of the gold, and MOST of the mass of the gold atom were concentrated. The nuclear age was born.
See here and links.
