Vitamin D has a percent composition of 42.98% C, and 57.02% H. Its molecular mass is 780.68 g/mol. Find its empirical and molecular formulas. Show your work.

Asample of silver (with work function ? = 4.52 ev) is exposed to an ultraviolet light source (? = 200 nm), which results in the ejection of photoelectrons. what changes will be observed if: silver is replaced with copper (? = 5.10 ev) more photoelectrons ejected no photoelectrons are emitted fewer photoelectrons ejected more energetic photoelectrons (on average) less energetic photoelectrons (on average)

How many molecules of sucrose c12h22o11 are there in 454 grams of sucrose

Agas in a balloon at constant pressure has a volume of 160 ml at -125*c. what is its volume at 29.0*c?