Which of the following is a nonrenewable fossil fuel?
- A. Coal
- B. Uranium
- C. Geothermal energy
- D. Ethanol
Correct Answer & Rationale
Correct Answer: A
Coal is a nonrenewable fossil fuel formed from ancient organic matter subjected to heat and pressure over millions of years. It is finite and cannot be replenished on a human timescale. Uranium (B) is a nonrenewable resource used in nuclear energy production but is not classified as a fossil fuel. Geothermal energy (C) harnesses heat from the Earth and is considered renewable. Ethanol (D) is a biofuel derived from plant materials, making it renewable as it can be produced continuously. Thus, coal stands out as the only nonrenewable fossil fuel in this list.
Coal is a nonrenewable fossil fuel formed from ancient organic matter subjected to heat and pressure over millions of years. It is finite and cannot be replenished on a human timescale. Uranium (B) is a nonrenewable resource used in nuclear energy production but is not classified as a fossil fuel. Geothermal energy (C) harnesses heat from the Earth and is considered renewable. Ethanol (D) is a biofuel derived from plant materials, making it renewable as it can be produced continuously. Thus, coal stands out as the only nonrenewable fossil fuel in this list.
Other Related Questions
Of the following gases, which is found in the atmosphere in the greatest concentration?
- A. O2
- B. N2
- C. H2
- D. CO2
Correct Answer & Rationale
Correct Answer: B
Nitrogen (N2) constitutes about 78% of the Earth's atmosphere, making it the most abundant gas. Oxygen (O2), while essential for life, is present at around 21%, significantly less than nitrogen. Hydrogen (H2) is found in trace amounts and is not a major component of the atmosphere. Carbon dioxide (CO2) is also present in much smaller concentrations, approximately 0.04%, and is primarily significant for its role in climate regulation. Therefore, nitrogen is the predominant gas, while the others are present in much lower concentrations.
Nitrogen (N2) constitutes about 78% of the Earth's atmosphere, making it the most abundant gas. Oxygen (O2), while essential for life, is present at around 21%, significantly less than nitrogen. Hydrogen (H2) is found in trace amounts and is not a major component of the atmosphere. Carbon dioxide (CO2) is also present in much smaller concentrations, approximately 0.04%, and is primarily significant for its role in climate regulation. Therefore, nitrogen is the predominant gas, while the others are present in much lower concentrations.
Which of the following best describes a comet?
- A. A small planet orbiting the Sun between Mars and Jupiter.
- B. A chunk composed primarily of metal that enters Earth's atmosphere.
- C. A chunk composed primarily of rock, ice, and dust orbiting the Sun in an elliptical path.
- D. A dark region that appears periodically on the surface of the Sun.
Correct Answer & Rationale
Correct Answer: C
Option C accurately describes a comet as a chunk composed primarily of rock, ice, and dust that orbits the Sun in an elliptical path. This definition captures the essential components and behavior of comets. Option A incorrectly defines a comet as a small planet, which is misleading; comets are distinct from asteroids and do not have the same characteristics. Option B describes a meteoroid, which is a metallic chunk entering Earth's atmosphere, not a comet. Option D refers to sunspots, which are dark regions on the Sun's surface, unrelated to comets. Each incorrect option misrepresents the nature of comets, highlighting the unique characteristics of these celestial bodies.
Option C accurately describes a comet as a chunk composed primarily of rock, ice, and dust that orbits the Sun in an elliptical path. This definition captures the essential components and behavior of comets. Option A incorrectly defines a comet as a small planet, which is misleading; comets are distinct from asteroids and do not have the same characteristics. Option B describes a meteoroid, which is a metallic chunk entering Earth's atmosphere, not a comet. Option D refers to sunspots, which are dark regions on the Sun's surface, unrelated to comets. Each incorrect option misrepresents the nature of comets, highlighting the unique characteristics of these celestial bodies.
Which of the following is a true statement about sodium chloride (NaCl)?
- A. It is a gas at room temperature.
- B. It is a compound formed from two elements.
- C. It is a mixture formed from two different compounds.
- D. It is an element that is unstable and reactive.
Correct Answer & Rationale
Correct Answer: B
Sodium chloride (NaCl) is indeed a compound formed from two elements: sodium (Na) and chlorine (Cl), which combine in a fixed ratio through ionic bonding. Option A is incorrect; NaCl is a solid at room temperature, not a gas. Option C misrepresents NaCl as a mixture, but it is a pure compound, not formed from different compounds. Option D inaccurately describes NaCl as an element; it is a stable compound, not unstable or reactive under normal conditions. Thus, option B accurately reflects the nature of sodium chloride.
Sodium chloride (NaCl) is indeed a compound formed from two elements: sodium (Na) and chlorine (Cl), which combine in a fixed ratio through ionic bonding. Option A is incorrect; NaCl is a solid at room temperature, not a gas. Option C misrepresents NaCl as a mixture, but it is a pure compound, not formed from different compounds. Option D inaccurately describes NaCl as an element; it is a stable compound, not unstable or reactive under normal conditions. Thus, option B accurately reflects the nature of sodium chloride.
A reaction occurs between two liquid substances in a sealed container. Based on the law of conservation of mass, what will happen to the mass of the sealed container and its contents overall?
- A. If the reaction produces a gas, the mass will decrease.
- B. If the reaction produces a solid, the mass will increase.
- C. If the reaction produces a liquid, the mass will increase as well.
- D. No matter what the reaction produces, the mass will remain the same.
Correct Answer & Rationale
Correct Answer: D
The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. Therefore, regardless of whether a gas, solid, or liquid is produced, the total mass of the sealed container and its contents will remain constant. Option A is incorrect; while gas may escape in an open system, a sealed container retains all products, so mass does not decrease. Option B is misleading; while a solid may form, it does not increase the total mass, as the mass of reactants equals that of products. Option C also misinterprets mass conservation; producing a liquid does not add to the total mass. Thus, the overall mass remains unchanged throughout the reaction.
The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. Therefore, regardless of whether a gas, solid, or liquid is produced, the total mass of the sealed container and its contents will remain constant. Option A is incorrect; while gas may escape in an open system, a sealed container retains all products, so mass does not decrease. Option B is misleading; while a solid may form, it does not increase the total mass, as the mass of reactants equals that of products. Option C also misinterprets mass conservation; producing a liquid does not add to the total mass. Thus, the overall mass remains unchanged throughout the reaction.