Correct Answer: D

Rationale: The van't Hoff factor (i) represents the number of particles a solute dissociates into in solution. For a compound that dissociates completely in water, i would be more than 1 because it breaks apart into more particles than the original compound. This is due to complete dissociation leading to an increase in the number of particles in solution, resulting in i being greater than 1. Choice A is incorrect as a compound that dissociates completely will not have an i value of 0. Choice B is incorrect because when a compound dissociates completely, the van't Hoff factor is not less than 1. Choice C is incorrect as a compound that dissociates completely will not have an i value of 1, but rather more than 1 due to the increased number of particles in solution.

Correct Answer: C

Rationale: The defining characteristic of an element is determined by the number of protons in its nucleus, which is referred to as the atomic number. The number of protons uniquely identifies an element. The correct answer is choice C because the number of protons in the nucleus of an atom defines its elemental identity, as different elements have a unique number of protons. Neutrons and electrons do play essential roles in the atom, but they do not determine the defining characteristic of an element. Neutrons contribute to the stability of the nucleus and isotopes of an element, while electrons are involved in chemical bonding and the reactivity of an atom.

Correct Answer: B

Rationale: Inertia is the resistance of an object to changes in its state of motion. The greater the mass of an object, the greater its inertia because it requires more force to change its state of motion. This concept aligns with Newton's first law of motion, which states that an object at rest will remain at rest, and an object in motion will continue in motion with the same speed and direction unless acted upon by an external force. Therefore, higher mass increases inertia, making it more difficult to alter the object's state of motion. Choice A is incorrect as mass does impact inertia. Choice C is incorrect as higher mass actually increases inertia, not decreases it. Choice D is incorrect as while mass does affect gravitational force, it also directly impacts inertia.

Correct Answer: B

Rationale: Atrophy is the correct answer as it is characterized by a wasting or decrease in muscle mass. Hypertrophy, on the other hand, refers to an increase in muscle size. Spasticity is associated with increased muscle tone due to continuous contraction of muscles. Myopathy, on the other hand, is a broad term used to describe various muscle diseases affecting muscle tissue, which may or may not involve muscle wasting.

Correct Answer: A

Rationale: When a wave enters a different medium, its frequency remains constant. Frequency is an intrinsic property of the wave determined by its source, and it does not change when transitioning between different mediums. On the other hand, wavelength, amplitude, and speed of the wave can all be altered when the wave moves from one medium to another. Wavelength is dependent on the speed of the wave and can change when entering a different medium due to differences in propagation speed. Amplitude can also change as it is influenced by factors like energy loss or gain at the boundary of the mediums. Speed, determined by the medium's properties, typically changes when a wave transitions between different mediums due to variations in the medium's density and elasticity.