Using the formula velocity = distance/time, how fast does sound travel in air at 20 degrees C given a distance of 500 m and 3.92 seconds. A- 3.92
B- 127 m/s
C- 2,941 m/s
D- 746 m/s

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it

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 bohr model of the atom explained why emission spectra are discrete. it could also be used to explain the photoelectric effect. which is a correct explanation of the photoelectric effect according to the model?