How many valence electrons are found on the outer most level of lithium (li)? a: 1 b: 2 c: 3 d: 4

Brad and his family like to go camping. they always take a gas lantern with them. the lantern can take fiuels but always puts out the same amount of light. brad has two different kinds of fuel for the lantern. how can he figure out which kind of fuel has more chemical energy that the lantern can turn into light? measure the brightness of the lantern using each kind of fuel by comparing it to the full moon. g measure the volume of the containers of fuel. measure how long the lantern stays lit on a fixed amount of fuel. measure the mass of each container of fuel using a balance scale. answer 12

Sulfuric acid (a component of acid rain) reacts with limestone (calcium carbonate) to produce calcium sulfate and carbon dioxide. this damages buildings and statues made of limestone. which solution of sulfuric acid will damage these structures more quickly? a. 0.001% b. 0.005% c. 0.010% d. 0.015%

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.)