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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)

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

What does the mass of 0.7891 mol of ferric oxide (fe2o3)