Which of the following substances is an element? F CO, G Nas H Co J KF​

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.)

Ahypothesis must be testable and falsifiable to be considered scientific a. trueb. false

Match each term to its description. match term definition excess reactant a) reactant that can produce a lesser amount of the product limiting reactant b) amount of product predicted to be produced by the given reactants theoretical yield c) reactant that can produce more of the product