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 Samarium, Sm, Lanthanide. Samarium is one of the less common of the rare earth elements, being on the one hand much less abundant than the other elements of the cerium group, and on the other hand much more abundant than europium, terbium, and thulium. It is about as plentiful as gadolinium. Samarium is a yellow metal of density 7. The metal quickly tarnishes in the air. Extracted by Mosander from ceria earth. The samarskite mineral was named.

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 Titanium, Ti, Transition Metal. Titanium occurs in the crust of the earth in the form of its dioxide, Ti. Which, like silica, is either in the free state or combined with metallic oxides, forming titanates. Impure titanium dioxide is found in three distinct crystalline forms as rutile, brookite, and anatase; ilmenite or titanic iron ore is Fe. Titanite or sphene, Ca. Igneous rocks contain an average of 0. 74 per cent, of Ti.

Element Zirconium, Zr, Transition Metal. Containing mineral hyacinth or a jargon from Sri Lanka, originally known as Ceylon has been known from deepest ages for its beautiful colors, from yellow-golden, brownish, to fumous-green. Hyacinth was considered to be a sort of topaz or ruby, with similar chemical compound, a gemstone now known as zircon. These minerals were not known to contain this element until Klaproth, in 1789, analyzed jargon. Was first prepared in 1914.

Element Hafnium, Hf, Transition Metal. In 1911 Urbain noticed several new lines in spectrum of the fractions of yttria mother solution and, thinking he had found a new element similar to the rare earths, called it celtium.

Element Lanthanum, La, Lanthanide. Lanthanum is a tin-white metal of density 6. It is malleable, but not ductile. Measurements made with material of doubtful purity indicate that lanthanum is feebly paramagnetic, but this is questionable. 923 and its heat of formation 97. it resembles the corresponding cerium compound.