I have a feeling that #2 is the one.
Do you have a picture of a diagram?
Explanation:
The number acquired by an element after the lose or gain of an electron is called oxidation number.
For example, 
Here, oxidation number of Fe(s) is 0 and Fe in
is +3.
Oxidation number of O in
is 0 as it is present in its elemental state.
The oxidation number of O in
is calculated as follows.

Hence, oxidation number of O in
is -2.
- The loss of electrons by an element or substance is called oxidation. Here, electrons are being lost by Fe(s) as an increase in oxidation state is occurring. So, Fe(s) is oxidized.
- The gain of electrons by an element or substance is called reduction. Here, electrons are being added to
as a decrease in its oxidation state is occurring. So,
is reduced.
- An element or compound which is being reduced is called oxidizing agent. Here,
is the oxidizing agent.
- An element or compound which is being oxidized is called reducing agent. Here, Fe(s) is the reducing agent.
Answer:
My chemistry teacher from my sophomore year.
Explanation:
I took class online last year and he was an older teacher and really didn't know how to use a computer. I asked for help multiple times and he would tell me to look the answer up. I would watch countless videos and still wouldn't understand. He ended up failing me that year and I had summer school. To this day, I dislike chemistry because of him.
60 seconds times 60 minutes is 3,600 seconds, or one hour. 3,600 times 2 is 7,200 seconds.