why are noble gas elements generally unreactive

ATI TEAS 7

TEAS version 7 quizlet science

1. Why are noble gas elements generally unreactive?

A. They are too large and cannot form bonds easily.
B. They lack valence electrons in their outermost shell.
C. They have strong bonds within their own molecules.
D. They have already achieved stable electron configurations.

Correct answer: D

Rationale: The correct answer is D. Noble gas elements are generally unreactive because they have already achieved stable electron configurations by having a full outer electron shell. This full shell makes them very stable and unlikely to gain, lose, or share electrons with other elements. Choices A, B, and C are incorrect because noble gases are not unreactive due to being too large to form bonds easily (A), lacking valence electrons in their outermost shell (B), or having strong bonds within their own molecules (C).

2. What happens to the density of a gas when its temperature increases at constant pressure?

A. It increases.
B. It decreases.
C. It remains the same.
D. Information is insufficient.

Correct answer: B

Rationale: When the temperature of a gas increases at constant pressure, the average kinetic energy of the gas molecules increases. This leads to the gas molecules moving faster and spreading out more, which causes them to occupy a larger volume. As a result, the density of the gas decreases because the same number of gas molecules are now distributed over a larger space. Choice A is incorrect because as the gas molecules spread out, the density decreases. Choice C is incorrect because the increase in temperature leads to a decrease in density due to the increased volume occupied by the gas molecules. Choice D is incorrect because with the provided scenario of temperature increase at constant pressure, the effect on density can be determined.

3. What is the difference between DNA and RNA?

A. Both are double-stranded.
B. DNA contains deoxyribose sugar, while RNA contains ribose sugar.
C. RNA contains the nitrogenous base uracil, while DNA contains thymine.
D. Both are identical molecules.

Correct answer: B

Rationale: A) Incorrect. DNA is double-stranded, but RNA is typically single-stranded. B) Correct. DNA contains deoxyribose sugar, which lacks an oxygen atom on the 2' carbon of the sugar ring, while RNA contains ribose sugar, which has an additional hydroxyl group on the 2' carbon. C) Incorrect. RNA contains the nitrogenous base uracil, while DNA contains thymine. D) Incorrect. DNA and RNA have distinct structures and functions, so they are not identical molecules.

4. What is the term for the process of bone formation and breakdown?

A. Ossification
B. Resorption
C. Remodeling
D. All of the above

Correct answer: C

Rationale: The correct term for the process of bone formation and breakdown is remodeling. Ossification specifically refers to bone formation, while resorption pertains to bone breakdown. Remodeling encompasses both processes, as it involves the continuous cycle of bone formation and resorption to maintain bone strength and structure. Choice A, 'Ossification,' is incorrect as it only refers to bone formation. Choice B, 'Resorption,' is incorrect as it only refers to bone breakdown. Choice D, 'All of the above,' is incorrect as it includes terms that are not comprehensive of both bone formation and breakdown.

5. Nuclear fusion powers the sun and other stars. What is the main obstacle to achieving controlled nuclear fusion on Earth for energy production?

A. Lack of suitable materials to handle high temperatures and pressures.
B. Limited availability of fusion fuels like deuterium and tritium.
C. Difficulty in containing the plasma where fusion occurs.
D. All of the above

Correct answer: D

Rationale: The main obstacle to achieving controlled nuclear fusion on Earth for energy production involves a combination of factors. A) Lack of suitable materials to handle high temperatures and pressures is a significant challenge due to the extreme conditions required for fusion reactions. B) Limited availability of fusion fuels like deuterium and tritium can pose a constraint on the scalability and sustainability of fusion energy. C) Difficulty in containing the plasma where fusion occurs is another critical issue as plasma instabilities and heat losses can hinder the efficiency of fusion reactions. Therefore, all of the options (A, B, and C) contribute to the challenges in achieving controlled nuclear fusion for energy production on Earth.