Which sound frequencies would a human ear be able to detect? Select all correct answers.

A. 0 10 Hertz
B. 100 Hertz
C. 1,000 Hertz
D. 10,000 Hertz

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

If you burn 46.6 g of hydrogen and produce 416 g of water, how much oxygen reacted

The ammonia molecule in the diagram has the observed bond orientation because