Nokea
In a phase diagram, what term is used for a substance held at a temperature and pressure where solid, liquid, and gaseous states of a substance exist simultaneously?
- A. critical temperature
- B. triple point
- C. absolute zero
- D. critical point
Correct Answer: B
Rationale: The point described in the question is called the triple point. At the triple point, all three phases of a substance (solid, liquid, and gas) coexist in equilibrium. The critical temperature is the highest temperature at which a distinct liquid phase can form, while absolute zero is the lowest possible temperature. The critical point is the point on a phase diagram that represents the highest temperature and pressure at which a distinct liquid and gas phase can coexist. Therefore, the correct answer is the triple point, where all three phases coexist.
You may also like to solve these questions
Which of the following microorganisms lacks its own metabolic pathways and can only reproduce inside a host cell?
- A. Bacteria
- B. Viruses
- C. Protozoa
- D. Muscle
Correct Answer: B
Rationale: The correct answer is B: Viruses. Viruses are obligate intracellular parasites, lacking metabolic pathways and being dependent on a host cell for replication. Unlike bacteria, protozoa, or muscle cells, viruses utilize the host cell's resources and machinery to replicate their genetic material and produce new viral particles.
The triple point of a substance is the temperature and pressure at which the substance exists as which of the following?
- A. As a gel with solid and liquid trapped in gas
- B. Simultaneously in sol, gel, and plasma phases
- C. Simultaneously in solid, liquid, and gas phases
- D. As a sol with gas and solid trapped in liquid
Correct Answer: C
Rationale: The triple point is a specific condition where a substance can exist simultaneously in all three phases: solid, liquid, and gas. The other options do not accurately describe this state.
A researcher writes a grant proposal to repeat an experiment that was recently published by another researcher. Which of the following statements best supports the grant proposal?
- A. Funding this grant proposal will allow for the continuation of studying this topic.
- B. Repeating the published work will provide independent confirmation of the results.
- C. Repeating published work with altered variables will extend the previous findings.
- D. Supporting this important research will be beneficial for science in the long term.
Correct Answer: B
Rationale: The best support for the grant proposal is that repeating the published work will provide independent confirmation of the results. This is crucial for scientific research as it strengthens the validity and reliability of the original findings. Independent confirmation is essential for verifying the reproducibility and credibility of the study. Options A, C, and D, though somewhat relevant, do not directly address the primary purpose of repeating the experiment for validation and verification in scientific research.
Which of the following tissues lines the interior surfaces of the heart?
- A. Epicardium
- B. Myocardium
- C. Endocardium
- D. Pericardium
Correct Answer: C
Rationale: The correct answer is C, Endocardium. The endocardium is the innermost layer of tissue that lines the interior surfaces of the heart, providing a smooth surface for blood flow. This smooth lining helps reduce friction as blood passes through the heart chambers. The epicardium is the outermost layer of the heart, the myocardium is the middle muscular layer responsible for the heart's contractions, and the pericardium is the protective sac surrounding the heart and providing support to the heart's structures.
Why is nitrogen gas an extremely stable molecule?
- A. resonance bonds
- B. ionic bonds
- C. triple covalent bonds
- D. hydrogen bonds
Correct Answer: C
Rationale: The correct answer is C - triple covalent bonds. Nitrogen gas (N2) is composed of two nitrogen atoms held together by a triple covalent bond. This bond is very strong and requires a significant amount of energy to break, making nitrogen gas a stable molecule. Triple covalent bonds involve the sharing of three pairs of electrons, resulting in a very stable configuration. Resonance bonds, ionic bonds, and hydrogen bonds are not present in the structure of nitrogen gas, hence they do not contribute to its stability.