10 A. How many years would pass if only 25% of the Potassium-40 radioactive elements are left? 10B. How many half-lives has the sample gone through if only 25% of the Potassium-40 radioactive elements are left?

If scientists are wrong about earth's age based on radioactive material and the decay rates are really much faster, how would nuclear power plants be affected?

Match the pollutants. 1. a chlorofluorocarbon smoke 2. a biodegradable organophosphate insecticide freon 3. particle pollution paint 4. hazardous waste monoxide 5. carbon is completely burned malathion 6. carbon is incompletely burned dioxide

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a.an ionic bond is formed between the oxygen and carbon atoms. b.four valence electrons are shared. c.two valence electrons are shared. d.valence electrons are shared between oxygen atoms.