Determine the mass of one drop of mercury by measuring the mass of 5 mL of mercury. Calculate the number of mercury molecules in one drop of mercury; m5 mL of Hg = 67.67 g. Assume 1 drop = 0.05 mL.

What are the charges of the subatomic particles by choosing the answer from the drop down menu. protons have a (+1,0,or-1). (protons, neutrons, electrons) have a 0 charge. 3.) electrons have a (+1,0,-1)

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

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.)