Element Barium, Ba, Alkaline Earth Metal. Has the combining weight 137. 4, and occurs naturally as sulphate and carbonate. Metallic barium is of a white colour, melts at a red heat, and reacts more energetically with water than strontium or calcium. We have here, therefore, a repetition of the same state of affairs as in the group of alkali metals, viz. the action with oxygen and oxygen compounds is more energetic the higher the combining weight of the metal. Barium forms only the divalent ion Ba.

Element Calcium, Ca, Alkaline Earth Metal. The element also takes part in the most varied way in the building up of the organisms. Calcium has also been found in meteorites, and by spectral analysis in the sun and fixed stars.

Element Strontium, Sr, Alkaline Earth Metal. Strontium forms only the divalent ion Sr. Whose solutions are colourless, and whose heat of formation is 501 kj. A very rare mineral, which before that could be found only in a couple of collections, named after the village of Strontian, Lochaber, Scotland. A mineral consisting of barium sulphate. He called the mineral strontianite.

Element Potassium K, Alkali Metal. While the knowledge of some of the potassium. After it had been obtained in this way, the method of preparing it by purely chemical means was soon discovered, a method which was for long the only one employed. The most important of these reactions is the heating of potassium carbonate with charcoal; carbon monoxide and metallic potassium. Are formed, the latter of which volatilises and is condensed under rock oil - K. It is a constituent of the waters of.

Element Caesium, Cs, Alkali Metal. Had undoubtedly been examined before, but had been mistaken by C. Plattner for potassium salts, meanwhile it was consisting of hydrous caesium. Pisani revealed it on the analysis of pollux in 1864.