Choose all the answers that apply. Hydrocarbons .

are poisonous
combine with nitrogen oxide to create smog
are mostly caused by cars
are part of the carbon-oxygen cycle
form when fuel is not completely burned

HURRY PL

How many atoms are there in 5.70 mol of mg

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.)

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?