Answer:
the increasing mass number
Volatile organic compounds can be detected by hydrogeologists in the field or labs because of the odor of the vapors emitted from the groundwater and/or soil samples.
<h3>What are volatile substances?</h3>
Volatile substances are substances which can easily vaporize or change to gaseous state.
Volatile substances can either be solids or liquids but are mostly liquids.
Example of volatile substances include ether, petrol, chocolate.
The presence of volatile substances can be detected by the gases they release which may have characteristic odors.
Therefore, volatile organic compounds can be detected by hydrogeologists in the field or labs because of the odor of the vapors emitted from the groundwater and/or soil samples.
Learn more about volatile compounds at: brainly.com/question/25403770
1-It has to be 3 Fe and not Fe3.
2-The oxygens aren't balanced
Balanced equation:
3Fe+4H2O---->Fe3O4+4H2
The redox reaction is

Here
Calcium undergoes reduction, and acts as cathode
Lithium undergoes oxidation and acts as anode
The reduction potential of calcium is -2.87 V
The reduction potential of lithium is - -3.05 V
We know that
Ecell = Ecathode - Eanode
Ecell = -2.87 - (-3.05) = 0.18 V