The table shows the doubling time of the world’s population throughout history.

Worldwide, the doubling time of the human population is about _.

40 to 50 years

7 to 10 years

100 to 150 years

30 to 40 months

Calcium hydride (cah2) reacts with water to form hydrogen gas: cah2(s) + 2h2o(l) → ca(oh)2(aq) + 2h2(g) how many grams of cah2 are needed to generate 45.0 l of h2 gas at a pressure of 0.995 atm and a temperature of 32 °c?

Which of the following statements about acidic water is true? a. acid has no effect on the h,o molecules. b. the solution contains a larger number of oh ions than h,o ions. c. the solution contains a larger number of h,o ions than qh ions. d. the solution contains an equal number of h,o ions and oh ions. none of the above e.

Imagine that you push on a large rock. at what point does your effort change the rock’s mechanical energy?