in an atom with more than one electron, what is the highest energy subshell in the second energy level?

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.