How many molecules are in a sample of sucrose that has a mass of 15.0 g

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)

Word equation for k+ h2o yield koh + h2

How will the volume of a gas be affected if the pressure is tripled, but the temperature remains the same?