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Stories About Chemistry

INDEX

8.  How Chemists Came Across the Unexpected

   You have probably read the splendid science­fiction novel by Herbert Wells called "The War of the Worlds," about the invasion of Earth by emissaries from Mars. You will recall that after the last Martian was killed and life on the Earth began to settle down again, the scientists, having recovered from the shocks they had undergone, hurried to study the little that was left of the unexpected visitors from the neighbouring planet. Among other things, they were interested in the mysterious black dust which the Martians used to destroy life on Earth. After several unsuccessful experiments which ended in terrible explosions, they found the ill­starred substance to be a compound of the inert gas argon with some elements not yet known on Earth.

   However, at the time the great writer of science fiction was putting the finishing touches to his book, chemists were absolutely certain that argon could not combine with anything under any conditions. A large number of practical experiments had brought them to this conclusion. Argon was called an inert gas. "Inert" comes from the Greek for "inactive." Argon is a member of a whole group of chemical sloths, which also includes helium, neon, krypton, xenon and radon. In the Periodic System they form what is known as the zero group, because the valence of these elements equals zero. The atoms of the inert gases are capable neither of donating nor of accepting electrons.