The decay of 40k has a half of 1.3 × 109 years. the age of the earth is estimated at 4.6 × 109 years. the decay of 40k is a major heat source for the earth's interior. relative to today, how much more heat was produced by 40k in the early archaeon era or 3.9 × 109 years ago?

Let the ed50 of a recreational drug be defined as the amount required for 50% of a test group to feel high or get a buzz. if the ed50 value of ethanol is 470 mg/kg body mass, what dose would a 70 kg party goer need to quickly consume in order to have a 50% chance of getting a buzz? 235 mg 470 mg 32,900 mg 35,000,000 mg