Pure copper metal has a very high conductivity. Brass, an alloy of copper and zinc, has a much lower conductivity. Why are the conductivities different? A.
because a chemical reaction has changed the copper into brass
B.
because the physical properties of the mixture are similar to its components
C.
because the physical properties of the mixture are different than its components
D.
because the copper is hidden by the zinc in the brass

Which scientists contributed to the determination of how cfcs in clouds in the upper atmosphere could destroy ozone molecules

How is it possible for someone to put an ear to a wall and hear someone in the next room?     a.sound waves can travel though solids.    b.the waves travel from room to room via air.    c.there must be some air in the wall so the sound can travel through it.    d.sound waves change to electromagnetic waves and then back again.

In the haber reaction, patented by german chemist fritz haber in 1908, dinitrogen gas combines with dihydrogen gas to produce gaseous ammonia. this reaction is now the first step taken to make most of the world's fertilizer. suppose a chemical engineer studying a new catalyst for the haber reaction finds that 671 liters per second of dinitrogen are consumed when the reaction is run at 271c and 0.99atm. calculate the rate at which ammonia is being produced. give your answer in kilograms per second. round your answer to significant digits.