Help asap pls! Circulating air caused when warm air rises and cool air sinks. Convection currents occur throughout the world. 1.barrage 2.collection area 3.convection current

What is the empirical formula of c6h18o3? ch3o c2h5o c2h6o c2h5o5

Which type of fossil does this image depict?

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.)