The flowchart below begins with the formation of coal and ends with the generation of electricity. List the substances that are released in emissions for each box in the chart.

1. No emissions

2. Methane, mercury and particulate matter, such as dust or soot, carbon monoxide, hydrocarbons, nitrogen oxides

3. Sulfur dioxide, nitrogen oxides, particulate matter (soot and ash), carbon dioxide, mercury, hydrocarbons, carbon monoxide, arsenic, lead, cadmium and other toxic heavy metals.

Explanation:

1. During the formation of coal there aren't any emissions. Coal is made up of carbon and hydrocarbons that contain energy but because there isn't any energy being used or released, there aren't any emissions during the formation process.  

2. The mining process of coal leads to the emissions of methane, mercury and particulate matter, such as dust or soot. Coal is predominantly transported by trains, trucks and barges. All of them run on diesel which lead to the emissions of carbon monoxide, hydrocarbons, nitrogen oxides and particulate matter.  

3. Burning coal to generate electricity leads to the emissions of sulfur dioxide, nitrogen oxides, particulate matter (soot and ash), carbon dioxide, mercury, hydrocarbons, carbon monoxide, arsenic, lead, cadmium and other toxic heavy metals.

I used the sources listed below to find my answers.

"How Coal Works". Union Of Concerned Scientists, 2021, https://www.ucsusa.org/resources/how-coal- works#:~:text=In%20addition%20to%20carbon%20dioxide,(smog)%20and%20respiratory%20illnesses. Accessed 17 Feb 2021.

"Coal And Air Pollution". Union Of Concerned Scientists, 2021, https://www.ucsusa.org/resources/coal-and-air-pollution. Accessed 17 Feb 2021.

"Coal And The Environment - U.S. Energy Information Administration (EIA)". Eia.Gov, 2021, https://www.eia.gov/energyexplained/coal/coal-and-the-environment.php#:~:text=In%202018%2C%20methane%20emissions%20from,coalbed%20methane%20extracted%20from%20mines. Accessed 17 Feb 2021.

i think that the answer is 5