Describe what subscripts and coefficients indicate in chemistry notation

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.)

Which of the following are sources of revenue for media companies? a. direct sales to producers b.advertising and subscriptions c. online purchase d. capital investments

Mercury metal is poured into a graduated cylinder that holds exactly 22.5 ml the mercury used to fill the cylinder mass in 306.0 g from this information calculate the density of mercury