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Home Q & A Board Science-Related Homework Help Chemistry (Moderator: Laser_3)
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thenamehobbs thenamehobbs
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5 months ago

The radioisotope potassium-40 decays to argon-40 by positron emission with a half-life of 1.3 × 109 yr. A sample of moon rock was found to contain 78 argon-40 atoms for every 22 potassium-40 atoms. The age of the rock is



▸

8.1 × 10–10 yr.



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2.4 × 109 yr.



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2.8 × 109 yr.



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4.6 × 109 yr.



▸

6.8 × 109 yr.

Textbook 
Chemistry: Atoms First

Chemistry: Atoms First


Edition: 4th
Author:
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thevoicexxxthevoicexxx
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5 months ago
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thenamehobbs Author
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5 months ago
Correct Slight Smile TY
Jose^2
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Yesterday
Good timing, thanks!
jblazah
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2 hours ago
this is exactly what I needed
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