Rust(Fe2O3) is produced when iron (Fe) reacts with oxygen(O2).
Equation: 4Fe(s) + 302(g) → 2Fe2O3(s)
How many grams of Fe2O3 are produced when 12.0 g of iron
rusts?

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 is the independent variable in this investigation? mass volume sample number substance density

Astudent conducts an experiment to determine how the amount of water given to a plant affects its growth. what is the independent variable for this experiment?