TEAS 7 science quizlet

Correct Answer: D

Rationale: The T wave on an ECG corresponds to ventricular repolarization. Following ventricular depolarization, which is represented by the QRS complex, the ventricles undergo repolarization during the T wave. This phase signifies the recovery of ventricular muscle cells as they prepare for the subsequent depolarization cycle. Choices A, B, and C are incorrect because the T wave specifically reflects the repolarization of the ventricles, not the atria or their respective depolarization or repolarization phases.

Correct Answer: A

Rationale: The balanced chemical equation indicates that 2 moles of sodium react with 2 moles of water to yield 2 moles of sodium hydroxide and 1 mole of hydrogen gas. When 3 moles of sodium react with only 2 moles of water, sodium becomes the limiting reactant as it is present in excess compared to the available water molecules. This situation arises because not all sodium atoms can fully react with the limited amount of water, resulting in sodium being the limiting reactant in this specific case. Choice B (H2O), choice C (NaOH), and choice D (H2) are incorrect as they are not the limiting reactant in the given reaction scenario.

Correct Answer: B

Rationale: A concentrated solution of a strong electrolyte is most likely to conduct electricity well. Strong electrolytes completely dissociate into ions in solution, allowing for the flow of electric current. This high concentration of ions in the solution enhances its conductivity, making it a better conductor compared to other options. A saturated solution, although containing dissolved ions, may not have a high enough concentration to conduct electricity effectively. A dilute solution of a weak acid is a poor conductor as weak acids only partially dissociate into ions. A mixture of a neutral compound and water does not contain free ions necessary for conducting electricity.

Correct Answer: C

Rationale: The correct answer is C, Diffraction. Diffraction is the phenomenon that explains the bending of waves around obstacles or through openings. When waves encounter obstacles or pass through openings, they spread out and bend around them. Reflection (Choice A) involves waves bouncing back when they encounter a surface without bending, refraction (Choice B) is the bending of waves when passing from one medium to another due to a change in speed, and absorption (Choice D) is the process of a wave being taken in by a material rather than bending or bouncing.

Correct Answer: C

Rationale: Dietary fiber refers to the indigestible portion of plant foods that passes relatively intact through the digestive system. While fiber does not directly provide energy to the body, it plays a crucial role in promoting the growth of beneficial gut bacteria. These bacteria help in the fermentation of fiber, producing short-chain fatty acids that can be used as an energy source by the body. Additionally, fiber aids in regulating bowel movements, maintaining gut health, and supporting overall digestive function. The functions described in the incorrect choices do not align with the primary role of dietary fiber in the digestive system. Choice A is incorrect because fiber itself is not a direct energy source. Choice B is incorrect as fiber does not break down fats. Choice D is incorrect because while fiber affects nutrient absorption indirectly by supporting gut health, its primary role is not to aid in the absorption of nutrients.