TESTBANK 2026/2027 AND HIGH YIELD PRACTICE QUESTIONS
COMPLETE ACCURATE EXAM APPROVED QUESTIONS AND
CORRECT VERIFIED SOLUTIONS (100% CORRECT VERIFIED
ANSWERS) CURRENTLY UPDATED VERSION 2026 EDITION
|GUARANTEED PASS A+ |FULL REVISED SKILLCAT EPA 608
REAL EXAM |JUST RELEASED
****This examination consists of 150 questions covering all
certification types.***
A passing score is 70% or higher.
1. What is the chemical formula of an ozone molecule?
A. O₂
B. O₃
C. CO₂
D. ClO
Correct Answer: B. O₃
Rationale: Ozone is a molecule composed of three oxygen atoms,
chemically represented as O₃. This is distinct from the oxygen we
breathe, which is O₂. The three-atom structure is what gives ozone its
unique properties in absorbing ultraviolet radiation in the
stratosphere .
,2. Where is the majority of Earth's ozone located?
A. Troposphere
B. Stratosphere
C. Mesosphere
D. Thermosphere
Correct Answer: B. Stratosphere
Rationale: Approximately 90% of Earth's ozone is found in the
stratosphere, which extends from about 10 to 50 kilometers above
the Earth's surface. This stratospheric ozone layer is crucial for
protecting life on Earth by absorbing harmful UV radiation. Ozone
in the troposphere (ground level) is considered a pollutant .
3. Which of the following is the primary source of chlorine in the
stratosphere?
A. Volcanic eruptions
B. Ocean evaporation
C. Emissions of refrigerants (CFCs and HCFCs)
D. Forest fires
,Correct Answer: C. Emissions of refrigerants (CFCs and HCFCs)
Rationale: While natural events like volcanic eruptions do contribute
some chlorine to the atmosphere, the primary source of chlorine in
the stratosphere is human-made emissions of chlorofluorocarbons
(CFCs) and hydrochlorofluorocarbons (HCFCs) used as refrigerants
and propellants. These compounds are stable enough to reach the
stratosphere where UV radiation breaks them down, releasing
chlorine atoms that destroy ozone .
4. Which molecule is primarily responsible for destroying the ozone
layer?
A. Oxygen
B. Nitrogen
C. Chlorine
D. Hydrogen
Correct Answer: C. Chlorine
Rationale: Chlorine atoms are the primary catalysts for ozone
destruction in the stratosphere. A single chlorine atom can destroy
up to 100,000 ozone molecules before being removed from the
stratosphere. This catalytic destruction cycle is why CFCs and
HCFCs, which release chlorine, are so harmful to the ozone layer .
, 5. One molecule of chlorine can destroy how many molecules of
ozone?
A. 1,000
B. 10,000
C. 100,000
D. 1,000,000
Correct Answer: C. 100,000
Rationale: Due to the catalytic nature of ozone destruction, one
chlorine atom can destroy approximately 100,000 ozone molecules.
The chlorine atom acts as a catalyst, being regenerated after each
reaction, allowing it to continue destroying ozone molecules
repeatedly. This demonstrates why even small amounts of CFCs in
the atmosphere have significant environmental impact .
6. Which of the following are effects of ozone layer depletion?
A. Increased rainfall and cooler temperatures
B. Decreasing crop yields and threats to wild and marine life
C. Improved air quality
D. Stronger hurricane activity