Elemental carbon has 6 protons and 6 neutrons. this is often described as carbon-12. carbon-13 has 6 protons and 7 neutrons, while carbon-14 has 6 protons and 8 neutrons. based on the trend with carbon and the fact that plutonium has 94 protons, how many neutrons are in radioactive plutonium-244? a. 102 neutrons b. 108 neutrons c. 150 neutrons d.338 neutrons

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.)

Consider the reduction reactions and their equilibrium constants. cu+(aq)+e−↽−−⇀cu(s)pb2+(aq)+2e−↽−−⇀pb(s)fe3+(aq)+3e−↽−−⇀fe(=6.2×108=4.0×10−5=9.3×10−3 cu + ( aq ) + e − ↽ − − ⇀ cu ( s ) k =6.2× 10 8 pb 2 + ( aq ) +2 e − ↽ − − ⇀ pb ( s ) k =4.0× 10 − 5 fe 3 + ( aq ) +3 e − ↽ − − ⇀ fe ( s ) k =9.3× 10 − 3 arrange these ions from strongest to weakest oxidizing agent.

How do temperature and salinity affect deepwater currents? as temperatures and salinity levels of water increase, the water rises to the surface where it creates currents as it moves to colder regions. they create changes in wind direction, moving denser water in the same direction as the wind and causing the deepwater circulation patterns found in the ocean. they equalize the forces on undersea currents caused by the coriolis effect as they replace more dense water with less dense water. they create density differences that cause dense deepwater currents to flow toward the equator where they displace less dense, warmer water above them.