What was the sensitive, well-insulated tool Willard F. Libby used to date artifacts with known ages?X-ray machineRichter scaleGeiger-Müller tubespetri dish

Willard F. Libby used Geiger-Müller tubes to detect the weak radiation from carbon-14 in samples. By testing artifacts with known ages, he could calibrate the method and use it to date other materials. An X-ray machine, Richter scale, and petri dish do not serve this radiation-detection purpose.

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