How often is Earth's surface being changed? 1 every hundred years
2 never
3 at all times
4 once a year

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)

Cucl2 + 2nano3 cu(no3)2 + 2nacl what is the percent yield of nacl if 31.0 g of cucl2 reacts with excess nano3 to produce 21.2 g of nacl? 49.7% 58.4% 63.6% 78.7%

The diagram below shows a cell placed in a solution.a cell is shown placed inside a beaker. it is labeled cell. the solution inside the beaker is labeled 40% salt solution and the solution inside the cell is labeled 20% salt solution.only water is allowed to move in and out of the cell. what will most likely happen to the cell? it will expand as water moves out of it. it will shrink as water moves out of it.it will expand as water moves into it. it will shrink as water moves into it.