What would the frequency be of a photon beam that had 4.72 x 10^8 joules of energy. Planck's constant is 6.6262 x 10^-34 joule* seconds

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

We are hoping to create 5.72 grams of glucose. the plant was given 4.75 liters of co2 and 2.81 g of h20. which reactant was the limiting reagent? how much excess mass did we have of the other reactant?

The semi-conductors on the periodic table are classified as