Classify the same processes as exothermic or endothermic.
Evaporation of alcohol from skin: liquid C3H30 +5.2 kJ → vaporized C3H30
Burning of propane in a gas grill: C3H8 +502 — 3C02 + 4H20 + 1652 kJ
Oxidation of iron to form rust 4Fe +30, 2Fe2O3 +2221 kJ

Explain which group an element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 belongs to.

What happens to isotopes that are unstable?

Consider the reaction of a(g) + b(g) + c(g) => d(g) for which the following data were obtained: experiment initial [a], mol/l initial [b], mol/l initial [c], mol/l initial rate, mol/l.s 1 0.0500 0.0500 0.0100 6.25 x 10^-3 2 0.100 0.0500 0.0100 2.50 x 10^-2 3 0.100 0.100 0.0100 1.00 x 10^-1 4 0.0500 0.0500 0.0200 6.25 x 10^-3 what is the rate law for the reaction?