The Discovery of Oxygen

For much of the eighteenth century chemists believed that when a substance burned in air a substance called phlogiston was released.  It was thought that a flame eventually went out in a closed container because the air became saturated with phlogiston. In August 1774, Priestley heated a red solid powder (mercury oxide) by using a…

Read More

Automobile Air Bags

Air bags are now widely used in automobiles in North America to protect the occupants in the event of a collision.  It is essential that the bag inflate very quickly: that is, within a few one-hundredths of a second.  Thus, the gas used must be produced by some very rapid reaction.  Moreover, that gas should…

Read More

Blast Furnaces

The Blast Furnace Iron ore, coke, and limestone are added at the top of the furnace, and air is blown in at the bottom.  The oxygen of the air reacts with the hot coke to form carbon monoxide.  This gas passes up the furnace, changing the iron oxide to iron as it moves down.  Liquid…

Read More

Antoine Laurent Lavoisier

Lavoisier was the son of a wealthy Parisian lawyer, who hoped that his son would follow him in that profession.  Although Lavoisier qualified as a lawyer in 1764, he became interested in science and he devoted much of his life to research in chemistry.  He is shown here with his wife, Marie-Anne Pierrette, who assisted…

Read More

Balloons

A balloon filled with any gas which is less dense than air will rise in the atmosphere. This is because the mass of the air displaced by the balloon is greater than the mass of the balloon itself. Since the density of the atmosphere decreases with increasing altitude, the balloon rises until the mass of…

Read More

Scientific Heresy

There are a lot of ideas in science that persist, even in the face of little or no experimental support.  For instance, the famous chemist Linus Pauling, recipient of two Nobel Prizes, suggested in 1970 that large doses of vitamin C would ward off the common cold.  As a side benefit, he claimed that this…

Read More