Question

1. how does lightning fixation occur?

a. lightning causes nitrogen gas molecules to break apart and react with oxygen.
b. lightning causes nitrogen gas molecules to break apart and react with carbon dioxide.
c. lightning causes nitrogen gas molecules to break apart and react with water.

1. what is denitrification?

a. the conversion of nitrite into atmospheric nitrogen
b. the conversion of nitrate into atmospheric nitrogen
c. the conversion of nitrite into nitrate

1. what human activities disrupt the natural nitrogen cycle?

a. overfishing and overharvesting crops
b. combustion of fossil fuels and excessive fertilizer use
c. driving electric cares and excessive overharvesting of crops

1. true or false: decomposers break down the organic matter and convert it into nitrate.

a. true
b. false

Explanation:

1. During lightning fixation, high - energy lightning causes nitrogen gas ($N_2$) molecules to break apart and react with oxygen to form nitrogen oxides.
2. Denitrification is the process where nitrate ($NO_3^-$) is converted into atmospheric nitrogen ($N_2$) by bacteria.
3. Combustion of fossil fuels releases nitrogen - containing compounds, and excessive fertilizer use adds excess nitrogen to the environment, disrupting the nitrogen cycle.
4. Decomposers break down organic matter and convert it into ammonia ($NH_3$), which can then be further converted into nitrate through nitrification.

Answer:

1. a. Lightning causes nitrogen gas molecules to break apart and react with oxygen.
2. b. the conversion of nitrate into atmospheric nitrogen
3. b. combustion of fossil fuels and excessive fertilizer use
4. b. false