What is the pOH of a solution with an OH- ion concentration of 8.4E-7?

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)

How does the principle of electromagnetism explain the interaction between earth’s magnetic field and the solar wind?

When balancing a chemical equation: