Clifford D Simak's "Tools" (novelette, free): Introducing very weird radioactive gaseous aliens

Key parts of this story involve Radon-222 gas, a natural radioactive decay product of radium, & the biggest cause of lung cancer among non smokers on earth. It also is the heaviest gas on earth, though its own decay products aren't gaseous. It's highly toxic.

Story summary.

Humans have been mining radium on Venus, where it's available in vast quantities. It's a key source of energy, & this mining business is a monopoly of Radium, Inc.

Someone discovered strange life-like properties in radon gas found there. In a lab, they've succeed, via special electrical sensors, to communicate with a bottled concentration of it. They've robotic mining devices whose brains are small confined concentrations of gas.

When the bottled gas intelligence in lab that has learned a lot about the human civilization leaks, gas all across Venus learns the things we know. So we have an adventure fighting an elusive omnipresent alien with completely unfamiliar thought processes.

Fact sheet.

First published: Astounding, July 1942.
Download full text as part of the scans of the magazine it originally appeared in.
Rating: B.
Among the stories from Analog/Astounding issues edited by John Campbell.
Related: Stories of Clifford D Simak.