Please answers quick!!

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)

In numbering carbon atoms in the parent chain of a hydrocarbon, why would you number from right to left, rather than left to right

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?