The beta decay of cesium-137 has a half-life of 30.0 years. How many years must pass to reduce a 25 mg sample of cesium 137 to 8.7 mg

An example of technology is the a. addition of a side group to an organic molecule during synthesis. b. use of a new antibiotic to fight an infection. c. measurement of iron concentration in a water sample. d. study of atomic fusion reactions

Over the last 90 years, scientists have added to the body of evidence supporting the big bang theory. what is the latest piece of evidence discovered in 2014?

Achemistry student needs to standardize a fresh solution of sodium hydroxide. he carefully weighs out of oxalic acid , a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in of distilled water. the student then titrates the oxalic acid solution with his sodium hydroxide solution. when the titration reaches the equivalence point, the student finds he has used of sodium hydroxide solution.calculate the molarity of the student's sodium hydroxide solution. be sure your answer has the correct number of significant digits.