Charcoal (burned wood) that was used to make prehistoric drawings on cave walls in france was scraped off and analyzed. the results were 8 mg-carbon-14 (parent isotope) and 56 mg hitrogen (daughter isotope). the half-life of carbon-14 is 5,730 years. how old are the cave drawings?

The following reaction shows the products when sulfuric acid and aluminum hydroxide react. al(oh)3 + h2so4 → al2(so4)3 + h2o the table shows the calculated amounts of reactants and products when the reaction was conducted in a laboratory. sulfuric acid aluminum hydroxide initial amount of reactant 40 g 15 g theoretical yield of water from reactant 14.69 g 10.38 g what is the approximate amount of the leftover reactant? 11.73 g of sulfuric acid 10.33 g of sulfuric acid 11.12 g of aluminum hydroxide 13.67 g of aluminum hydroxide

An observation that requires measurement is called quantitative observable or qualitative

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.)