1.5 - THE NITROGEN CYCLE

Question 1

Which of the following statements is TRUE in regards to atmospheric nitrogen and its relationship with living organisms?

a) N₂ is a respiratory irritant that can trigger asthma attacks and cause lung tissue damage.
b) N₂ is a greenhouse gas that is increasing in concentration on Earth causing issues with sea level rise, drought, and increased storm intensity.
c) N₂ is a key component to photochemical smog.
d) N₂ contains a strong triple bond that makes it unable to react within organisms.

Answer 1

Nitrogen belongs to an exclusive group on the periodic table called diatomics. These are elements that are not usually found in nature alone. These elements will bond with another atom of the same kind to form two (di) atoms (atomic).

In nitrogen’s case, the two nitrogen atoms form a triple bond that is so strong that it cannot be broken down inside living things and makes it essentially inert (does not react). The correct answer is Choice D.

Question 2

During nitrogen fixation, soil bacteria convert nitrogen to ammonia.

What is the chemical formula for ammonia?

a) NO₂
b) NH^-1₂
c) NH₃
d) NH⁺¹₄

Answer 2

Choice C is correct.

Question 3

Which of the following types of plants is MOST likely to contain nitrogen fixing bacteria?

a) Oak tree.
b) Corn plant.
c) Pine tree.
d) Peanut bush.

Answer 3

Choice D is the correct answer.

Legumes, like peanuts, beans, peas, etc., are most likely to have nitrogen-fixing bacteria in their roots.