Given a 800 mg sample of thorium-231 decomposes via beta emission with a half life of 25.5 hours, how long would it take, in days, for the sample to decay down to 25 mg?

231 0 231

th - > beta pa

90 - 1 91

800 mg / 25 mg

What best explains the reason solids have a definite shape and volume? A. the molecules in solids move past each other easily. B. the molecules in solids stay in a definite location and vibrate. C.

Question 13 A chemistry student needs 60.0mL of pentane for an experiment. By consulting the CRC Handbook of Chemistry and Physics, the student discovers that the density of pentane is ·0.626gcm-3.

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