Air in a cylinder is compressed (volume is reduced and pressure increased) by moving a piston. In our sign convention, is this work positive or negative?.

Ametal with a large number of free flowing electrons most likely has good conductivity

Just took the quiz on edgenuity and the correct answer is "c.  4.54 x  10–12  j"

Answer is: hydrogen is being oxidized.chemical reaction: co₂ + h₂ → co + h₂o.oxidation half reaction: h₂ → 2h⁺ + 2e⁻.reduction half reaction: c⁺⁴ + 2e⁻ → c⁺².oxidation is increase of oxidation number, hydrogen change oxidation number from neutral charge (in molecule of hydrogen) to oxidation number +1 (in water).