The average propane cylinder for a residential grill holds approximately 18 kg of propane. how much energy (in kj) is released by the combustion of 20.00 kilograms of propane in sufficient oxygen?

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)

What’s the percent by mass of carbon in c10h14n2

What is the relation between concentration of reactants and the rate of chemical reaction?