How many grams are in 0.002 moles of barium nitrate, Ba(NO3)2

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 grams of cupric sulfate pentahydrate are needed to prepare 50.00 ml of 0.0800m cuso4× 5h2o?

Using the periodic table complete the table to describe each atom type in your answers