By what factor does the average kinetic energy of helium atoms in a balloon change as the helium gas is heated from -100.0°C to 73°C? Show all calculations.

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.)

Use the half-reactions of the reaction au(oh)3 + hi -> au +i2 +h2o to answer the questions

Need ! assume that the variables x and y are directly related. if k = 8, what is the value for each of the following points? be sure and record your data to be used in the following problem. x y k 0.