A chemist measures the amount of iodine solid produced during an experiment. He finds that 285. g of iodine solid is produced. Calculate the number of moles of iodine solid produced.

A100-watt light bulb radiates energy at a rate of 100 j/s. (the watt, a unit of power or energy over time, is defined as 1 j/s.) if all of the light emitted has a wavelength of 525 nm , how many photons are emitted per second?

Compare and contrast physical changes with chemical changes.

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.