Can anyone please give me the correct answers for these questions.

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)

Determine the mass of fuel required for the expected energy consumption in the united states for the next ten years. energy use per person per year in the united states = 3.5 x 1011joules base calculations on current population of 310,000,000.

Explain which group an element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 belongs to.