There are two meanings to the word "Distal"
Anatomy
- situated away from the center of the body or from the point of attachment.
Geology
2. relating to or denoting the outer part of an area affected by geological activity.
For the reactants,
- The oxidation number of hydrogen = +1
- The oxidation number of oxygen = -2
- The oxidation number of arsenic = +5
- The oxidation number of carbon = +3
For the products,
- The oxidation number of hydrogen = +1
- The oxidation number of oxygen = -2
- The oxidation number of arsenic = +3
- The oxidation number of carbon = +4
Here, arsenic (+5 to +3) and carbon (+3 to +4) are the only oxidation numbers changing.
Note that an increase in oxidation number means electrons are lost. Thus oxidation is occurring, and a decrease in oxidation number means electrons are being gained, and thus reduction is occurring.
Also, the compound that contains the element being oxidized is the reducing agent, and the compound that contains the element being reduced is the oxidizing agent.
So, the answers are:
name of the element oxidized: Carbon
name of the element reduced: Arsenic
formula of the oxidizing agent: 
formula of the reducing agent: 
Heat energy is the amount of heat there is in a substance. This may be cold heat or warm heat. Temperature is how hot or cold a substance is. So because there is a higher volume of heat in the iceberg, we say it has more heat energy.