The force of a gas's outward push divided by the area of the walls of the container is the gas's

Jewelweed, a flowering plant, has seed pods that burst open when touched and forcefully eject their seeds. these structures are favorable because they a. can cause genetic changes to occur. b. prevent germination within the seed pod. c. aid in the dispersal of the species. d. attract insects that aid in pollination.

Frictional forces acting on an object are often converted into energy, which causes the temperature of the object to rise slightly.

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.)