In 1908, a huge explosion known as the Tunguska Event flattened trees for miles across a remote area of Russia. Scientists now think an asteroid or a comet entered Earth's atmosphere, causing the explosion. Ice core samples from an ice sheet in Greenland reveal signs of this enormous explosion: deposits of ammonia equal to 5 micrograms per square meter. But how exactly did these telltale molecules form?
• Hypothesis 1: The Tunguska explosion started forest fires, known to produce ammonia. Data indicates that such fires would have deposited an amount of ammonia over the Northern Hemisphere equaling 0.1 micrograms per square meter.
• Hypothesis 2: Up to 1% of the object's mass might have been ammonia, and this ammonia might have spread over the Northern Hemisphere. Approximately 0.00005 micrograms of ammonia per square meter are predicted by this hypothesis.
• Hypothesis 3: Since many compounds form in the presence of high heat, the ammonia could
have been produced as the falling object heated the atmosphere. However, heat alone is not
sufficient to cause the formation of ammonia.
• Hypothesis 4: As it passed through the atmosphere, the object pushed air in front of it at high pressure. Nitrogen and hydrogen combine to form ammonia under similar pressure. Considering the amount of hydrogen expected in a comet and the available nitrogen in Earth's atmosphere, approximately 5 micrograms of ammonia per square meter would have been deposited under this hypothesis.
Scientists have estimated the mass of the object that caused the Tunguska Event at 5 x 10^12 kilograms (kg). If the object was a comet in which 1% of total mass was ammonia, how much ammonia did the comet contain? kg
Correct Answer & Rationale
Correct Answer: 5x10^10
To find the mass of ammonia in the comet, we calculate 1% of the total mass (5 x 10^12 kg). This is done by multiplying the total mass by 0.01: 5 x 10^12 kg × 0.01 = 5 x 10^10 kg. This calculation confirms that the comet contained 5 x 10^10 kg of ammonia. Other options may result from incorrect calculations, such as misunderstanding the percentage or misapplying the multiplication. For instance, using 0.1 instead of 0.01 would yield an answer ten times larger, while failing to convert the percentage to a decimal would also lead to an incorrect figure.
To find the mass of ammonia in the comet, we calculate 1% of the total mass (5 x 10^12 kg). This is done by multiplying the total mass by 0.01: 5 x 10^12 kg × 0.01 = 5 x 10^10 kg. This calculation confirms that the comet contained 5 x 10^10 kg of ammonia. Other options may result from incorrect calculations, such as misunderstanding the percentage or misapplying the multiplication. For instance, using 0.1 instead of 0.01 would yield an answer ten times larger, while failing to convert the percentage to a decimal would also lead to an incorrect figure.
Other Related Questions
A 60W light bulb used .48 kilowatt hours of electricity. How long was the light bulb on?
- A. 0.48 hours
- B. 28.8 hours
- C. 0.125 hours
- D. 8 hours
Correct Answer & Rationale
Correct Answer: D
To determine how long the 60W light bulb was on, we first convert the energy used from kilowatt hours to watt hours: 0.48 kWh equals 480 watt hours. Using the formula: time (hours) = energy (watt hours) / power (watts), we calculate: 480 watt hours / 60 watts = 8 hours. Option A (0.48 hours) underestimates the time significantly. Option B (28.8 hours) incorrectly suggests the bulb was on much longer than the energy consumed allows. Option C (0.125 hours) miscalculates by assuming a much higher power consumption. Only option D accurately reflects the time the bulb was on based on the energy used.
To determine how long the 60W light bulb was on, we first convert the energy used from kilowatt hours to watt hours: 0.48 kWh equals 480 watt hours. Using the formula: time (hours) = energy (watt hours) / power (watts), we calculate: 480 watt hours / 60 watts = 8 hours. Option A (0.48 hours) underestimates the time significantly. Option B (28.8 hours) incorrectly suggests the bulb was on much longer than the energy consumed allows. Option C (0.125 hours) miscalculates by assuming a much higher power consumption. Only option D accurately reflects the time the bulb was on based on the energy used.
Placing solid ammonium nitrate, NH4NO3, in a container of water causes an endothermic reaction. The result is ammonium hydroxide, NH4OH, and nitric acid, HNO3. Which diagram shows the correct equation for the reaction?
- A. NH4OH + HNO3 → NH4NO3 + H2O + energy
- B. NH4NO3 + H2O + energy → NH4OH + HNO3
- C. NH4NO3 + H2O → NH4OH + HNO3 + energy
- D. NH4OH + HNO3 + energy → NH4NO3 + H2O
Correct Answer & Rationale
Correct Answer: B
The reaction involving solid ammonium nitrate and water is endothermic, meaning it absorbs energy. Option B accurately reflects this by showing ammonium nitrate and water reacting to form ammonium hydroxide and nitric acid while requiring energy input, consistent with the endothermic nature of the process. Option A incorrectly suggests that energy is released, which contradicts the reaction's endothermic characteristic. Option C also misrepresents the energy aspect, implying that energy is produced, which is not the case. Option D similarly indicates that energy is released, misaligning with the reaction's true nature.
The reaction involving solid ammonium nitrate and water is endothermic, meaning it absorbs energy. Option B accurately reflects this by showing ammonium nitrate and water reacting to form ammonium hydroxide and nitric acid while requiring energy input, consistent with the endothermic nature of the process. Option A incorrectly suggests that energy is released, which contradicts the reaction's endothermic characteristic. Option C also misrepresents the energy aspect, implying that energy is produced, which is not the case. Option D similarly indicates that energy is released, misaligning with the reaction's true nature.
Limestone and marble are often used in buildings. Both types of rock contain calcium carbonate, which is sensitive to chemical weathering by acids. A scientist conducted an experiment to test the effect of acid strength on calcium carbonate... Which change would reduce the possibility of error in the experiment?
- A. performing the experiment with a different acid in the solution
- B. performing multiple trials for each solution pH
- C. using more of the acidic solution
- D. using a solution with a pH below 3.00
Correct Answer & Rationale
Correct Answer: B
Performing multiple trials for each solution pH enhances the reliability of the experiment by allowing for the identification of consistent patterns and minimizing the impact of random errors. This approach provides a more accurate average result, leading to valid conclusions about the effect of acid strength on calcium carbonate. Option A introduces a variable that may not be relevant to the original question, potentially complicating the results. Option C does not address the variability inherent in a single trial, which could skew results. Option D restricts the experiment to a specific range of acidity, limiting the exploration of acid strength effects across a broader spectrum.
Performing multiple trials for each solution pH enhances the reliability of the experiment by allowing for the identification of consistent patterns and minimizing the impact of random errors. This approach provides a more accurate average result, leading to valid conclusions about the effect of acid strength on calcium carbonate. Option A introduces a variable that may not be relevant to the original question, potentially complicating the results. Option C does not address the variability inherent in a single trial, which could skew results. Option D restricts the experiment to a specific range of acidity, limiting the exploration of acid strength effects across a broader spectrum.
Which statement describes a weakness of the investigation in the passage?
- A. None of the hypotheses are directly related to the ice core data.
- B. The Greenland ice sheet is far away from the site of the explosion in Russia.
- C. Several of the hypotheses rely on unproven processes or estimated values.
- D. A few micrograms of ammonia is insufficient evidence for a conclusion.
Correct Answer & Rationale
Correct Answer: C
Option C highlights a significant weakness, as relying on unproven processes or estimated values can lead to unreliable conclusions, undermining the investigation's credibility. Option A is incorrect because hypotheses can be related to data in broader contexts, even if not directly. Option B misrepresents the geographical relevance; distance alone does not invalidate the connection between the ice core data and the explosion. Option D, while suggesting a concern about evidence quantity, does not address the fundamental issue of reliance on unproven processes that can skew the investigation's outcomes.
Option C highlights a significant weakness, as relying on unproven processes or estimated values can lead to unreliable conclusions, undermining the investigation's credibility. Option A is incorrect because hypotheses can be related to data in broader contexts, even if not directly. Option B misrepresents the geographical relevance; distance alone does not invalidate the connection between the ice core data and the explosion. Option D, while suggesting a concern about evidence quantity, does not address the fundamental issue of reliance on unproven processes that can skew the investigation's outcomes.