- Element F - Gaseous element - A non-metallic, gaseous element, strongly acid or
negative, or associated with chlorine, bromine, and iodine, in the
halogen group of which it is the first member. It always occurs
combined, is very active chemically, and possesses such an avidity for
most elements, and silicon especially, that it can neither be prepared
nor kept in glass vessels. If set free it immediately attacks the
containing material, so that it was not isolated until 1886. It is a
pungent, corrosive, colorless gas. Symbol F. Atomic weight 19.
- Element Na - Element with symbol Na - Salt, ... chloride - Silvery-white element - A common metallic element of the alkali group, in nature
always occuring combined, as in common salt, in albite, etc. It is
isolated as a soft, waxy, white, unstable metal, so readily oxidized
that it combines violently with water, and to be preserved must be kept
under petroleum or some similar liquid. Sodium is used combined in many
salts, in the free state as a reducer, and as a means of obtaining
other metals (as magnesium and aluminium) is an important commercial
product. Symbol Na (Natrium). Atomic weight 23. Specific gravity 0.97.