Which statement about exothermic reactions is correct?
a. Energy is always created in the form of heat.
B. Energy is transferred from the surroundings to the reactants.
C. Energy is used to force electrons to move to higher energy levels.
D. Energy is transferred from the reactants to the surroundings.

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)

What are the major products produced in the combustion of c10h22 under the following conditions? write balanced chemical equations for each. a. an excess of oxygen b. a slightly limited oxygen supply c. a very limited supply of oxygen d. the compound is burned in air

Compare the valence electron configuration of the nobles gas elements seen here. what statement is correct?