A radioactive isotope has a half-life of 3 hours. If a scientist has 30 grams of the isotope, how much is left after 15 hours

Why is particle size important in a heterogeneous catalyst

Berny has a 0.15-kilogram candle, a 1.00-kilogram jar, and a 0.25 kilogram candle holder. He places the candle and candle holder in the jar, lights the candle, and then immediately closes the jar.

In what beaker does the sugar dissolve the fastest? (particle size, temp. of water, condition (stir/no stir), etc).

Which statement best describes the kinds of questions we can use science to answer? A. No questions about natural phenomena B. Any and all questions C. Only philosophical questions D. No questions about right and wrong

If aqueous solutions of lead (II) nitrate and sodium sulfate, which insoluble precipitate is formed? Select one: a. NaNO3 b. Na2NO3 c. PbSO4 d. Pb2SO4 e. PbS

What is the theoretical empirical formula of magnesium oxide

8. which change in state is associated with the heat of vaporization, 1. solid to liquid 2. liquid to vapor 3. solid to vapor 4. liquid to solid

A mixture of calcium carbonate, CaCO3, and barium carbonate, BaCO3, weighing 5.40 g reacts fully with hydrochloric acid, HCl (aq), to generate 1.39 L CO2 (g), mea sured at 50°C and 0.904 atm pressure.

Which of the following is the major advantage of using geothermal energy instead of using coal energy? Choice: You will get a brainliest! If your correct! A. More abundant than coal B. Easier to access than coal C. Releases less carbon dioxide D.

Why can equilibrium not be reached in reversible enzymatic rxn?