Rubidium
Videos
Rubidium is a chemical element; it has symbol Rb and atomic number 37. It is a very soft, whitish-grey solid in the alkali metal group, similar to potassium and caesium. Rubidium is the first alkali m
Rb 5
Partially molten rubidium metal in an ampoule
Rubidium crystals (silvery) compared to caesium crystals (golden)
Flame test for rubidium
Potassium
Videos
Potassium is a chemical element; it has symbol K and atomic number 19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxyge
Rubidium
…Rubidium is a chemical element; it has symbol Rb and atomic number 37. It is a very soft, whitish-grey solid in the alkali metal group, similar to potassium and caesium. Rubidium is the first alkali metal in the group to have a density higher than water. On Earth, natural rubidium comprises two isotopes…
Potassium pearls (in paraffin oil, ~5 mm each)
Sir Humphry Davy
Pieces of potassium metal
Potassium in feldspar