Correct Answer: B

Rationale: The correct answer is 'B: Kilowatt-hour (kWh).' The kilowatt-hour is a unit commonly used to measure electricity consumption, representing energy usage over time. A Pascal (Pa) is a unit of pressure, Coulomb (C) is a unit of electric charge, and Tesla (T) is a unit of magnetic flux density. Therefore, the kilowatt-hour is the appropriate unit for measuring work and energy in this context.

Correct Answer: B

Rationale: In meiosis, there are two divisions: meiosis I and meiosis II. During meiosis I, homologous chromosomes separate, resulting in two daughter cells with half the number of chromosomes as the parent cell. In meiosis II, sister chromatids separate, resulting in a total of four daughter cells, each with a haploid set of chromosomes. Therefore, meiosis involves two divisions and produces four daughter cells. Choice A is incorrect because meiosis involves two divisions, not one. Choice C and D are incorrect as meiosis does not go through four or eight divisions, resulting in eight or sixteen daughter cells.

Correct Answer: B

Rationale: The group number of an element on the periodic table corresponds to the number of valence electrons it has. Elements in the same group tend to form ions with the same charge. For example, elements in Group 1 typically form ions with a +1 charge, while elements in Group 17 typically form ions with a -1 charge. Therefore, by identifying the group number of an element, one can predict the typical ionic charge it will form. Choices A, C, and D are incorrect because predicting the charge of an ion is mainly based on the element's position in the periodic table, particularly the group number, which indicates the number of valence electrons and the typical ionic charge it may form.

Correct Answer: C

Rationale: Friction is a force that opposes motion. When two surfaces are in contact, friction acts in the opposite direction to the motion or the potential motion between the two surfaces. It resists the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Friction hinders or prevents motion rather than promoting it. Choices A, B, and D are incorrect as they suggest that friction increases, accelerates, or creates motion, which is inaccurate. The correct definition of friction is that it opposes motion, making choice C the most appropriate option.

Correct Answer: B

Rationale: The correct answer is B, the cerebellum. The cerebellum plays a crucial role in coordinating muscle movements, maintaining balance, and posture. It receives inputs from sensory systems, the spinal cord, and other brain regions to fine-tune motor movements. The cerebrum, choice A, is primarily involved in higher brain functions like thinking and decision-making. The medulla oblongata, choice C, controls essential functions such as breathing and heart rate. The thalamus, choice D, serves as a relay center for sensory information but is not directly responsible for coordinating muscle movements, balance, or posture.