The radioactive element carbon-14 has a half-life of 5750 years. A scientist determined that the bones from a mastodon had lost 67.6% of their carbon-14. How old were the bones at the time they were discovered?

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What best discribes the relationship between wavelength and frequency in a electromagnetic wave

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.