Soot particles: A. are also called black carbon; B. are mostly in the coarse…
2023
Soot particles:
A. are also called black carbon;
B. are mostly in the coarse size range;
C. are toxic;
D. contribute to global warming; and
E. can penetrate into deeper parts of the lungs.
Choose the correct answer from the options given below:
Answer: C. A, C, D, E only — ConceptSoot is a carbon-rich particulate product of incomplete combustion. Particulate pollution is assessed through composition, aerodynamic size, biological…
- A.
A, B, C, D only
- B.
A, B, C, E only
- C.
A, C, D, E only
- D.
B, C, D, E only
Show answer & explanation
Correct answer: C
Concept
Soot is a carbon-rich particulate product of incomplete combustion. Particulate pollution is assessed through composition, aerodynamic size, biological effects, and interaction with radiation.
Fine and ultrafine particles can travel deep into the respiratory tract, while strongly light-absorbing black carbon warms the atmosphere and can accelerate melting after deposition on snow or ice.
Application
Statement A: In standard environmental-science usage, soot is commonly referred to as black carbon, although technically black carbon is the strongly light-absorbing component of soot.
Statement B: Soot occurs mainly in the fine and ultrafine particulate range, so describing it as mostly coarse is inconsistent with its usual aerodynamic-size distribution.
Statement C: Soot can carry reactive and toxic combustion products; inhalation can produce oxidative stress, inflammation, and cardiopulmonary harm.
Statement D: Black carbon absorbs incoming solar radiation and converts it to heat, giving it a positive warming effect in the atmosphere.
Statement E: Because soot particles are predominantly fine, they can pass beyond the upper airways and deposit in deeper regions of the lungs.
Contrast the offered combinations
Combination | Comparison |
|---|---|
A, B, C, D only | A, B, C, D only retains the coarse-size claim B and leaves out the deep-lung claim E. |
A, B, C, E only | A, B, C, E only retains the coarse-size claim B and leaves out the warming claim D. |
A, C, D, E only | A, C, D, E only excludes the coarse-size claim B while retaining the naming, toxicity, warming, and deep-lung claims. |
B, C, D, E only | B, C, D, E only retains the coarse-size claim B and leaves out the black-carbon naming claim A. |
Cross-check
The same size property provides an independent check: particles capable of reaching the deeper lung are associated with the fine fraction, not a predominantly coarse fraction. Thus B conflicts with E-supported particulate behaviour.
Therefore, the supported set is A, C, D, E only.