Mary Gausman, age 12, of St. Paul, Minnesota, for his question:
What is boron and how is it useful?
The light brown crystals of pure boron are rarely seen in the everyday world. But, we are on good terms with two boron compounds and many others Oerform useful chores behind the scenery of industry. Their roles range from weed killing to rocketing.
Boron is not among the most plentiful or the rarest of elements. It makes up less than a thousandth of a per cent of the earth's crustal rocks and we never find it in its pure form. Its small atoms readily unite with other elements to form molecules of boron compounds. One of these natural compounds is borax, found strewn throughout many of our western deserts. Borax has been used for generations as a water softener in the laundry tub. Another house¬hold boron compound is boric acid, the only acid weak enough to be used safely as an eye lotion.
Pure boron is a non metallic element related to carbon and silicon. The boron and carbon families bridge the gap between metallic and non metallic elements. Boron has the atomic number S. It has a complete inner shell of two electrons. Its second shell has only three electrons to occupy the spaces for eight. The physical properties and chemical behavior of boron are triggered by the vacant spaces in this second electron shell.
Plant life separates small amounts of boron from its natural compounds. More is separa¬ted by chemical processes. America mines a million tons of boron a year and, strange to say, large doses of this vital plant life element are used in weed killers. The pure element comes in brownish crystals and becomes an ingredient in dozens of useful compounds. Much of it is hidden in space age metals. It adds hardness to steel alloys and heat resistance to such metals as tungsten and titanium. These light, durable alloys take off in jets and rockets.
Boron hydrogen compounds burn with terrific heat, making them valuable additives in gasoline fuels. Boron carbide, fused from boron and carbon, forms a hard abrasive, and boron fused with nitrogen forms a substance as hard as a diamond. A boron silicon compound is an ingredient in oven proof glassware.
The little boron atom plays its most dramatic role in a nuclear reactor. It absorbs neutrons zooming off from nuclear fission. Boron rods are poked into the atomic pile to control the rate of nuclear activity. When the atomic furnace needs boosting, the rods are partly withdrawn to allow flying neutrons to generate more fission activity. When the furnace needs cooling, they are poked deeper into the pile.
Sodium borate, alias borax, has been used for ages to make hard and glossy ceramic glazes. It also is an ingredient in certain shiny enamel paints. And rock hounds have a use for the old standby. It is used in the positive identification of certain metals. When borax crystals are dipped in a solution containing chromium and heated in a flames aw• green colored compound is formed. The same process causes cobalt to form a blue compound and nickel one of muddy brown.