help 4 me ples??? What science law explains why there should always be the same type of elements on the reactant side as there are on the product side? What does this law state? (HINT: Answer both of these questions. A: The Law of states that .)

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)

If 1.8 l of water is added to 2.5l of a 7.0 m koh solution, what is the molarity of the new solution

Given the following reaction: c3h8+5o2=3co2+4h20 how many grams of co2 will be produced 7 g of c3h8 and 98 g of o2