Half of a substance will decay after 10 hours. If 150 g of a substance is present inititially, how much would be left after 3 days? (half-life decay)

In an experiment you are to flip a two sided coin 100 times and record 55 heads up and 45 tails up determine the theoretical and experimental probability of getting a heads up in the experiment.

If the speed of an electromagnetic wave is 100,000 cm/s and its wavelength is 100 cm, what is its frequency? a) 100,000 cycles per second (hz) b) 1 × 10-3 cycles per second (hz) c) 10,000,000 cycles per second (hz) d) 1,000 cycles per second (hz)

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees