Which statement describes a chemical property that can be used to distinguish between compound a and compound b?
(1) a is a blue solid, and b is a white solid.
(2) a has a high melting point, and b has a low melting point.
(3) a dissolves in water, and b does not dissolve in water.
(4) a does not burn in air, and b does burn in air.

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)

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.

What type of reaction fuels the processes seen here?