Correct Answer: C

Rationale: A chemical change involves a chemical reaction where new substances are formed. Burning wood to produce ash is an example of a chemical change because the wood undergoes a chemical reaction to form a new substance (ash). In this process, the chemical composition of wood changes to produce ash, which is a new substance. On the other hand, melting ice to form water, dissolving sugar in water, and crushing a can to reduce its size are examples of physical changes. In these instances, the substances may change their physical state or appearance but do not undergo a chemical reaction to form new substances. Therefore, choice C is the correct answer as it represents a chemical change, while choices A, B, and D represent physical changes.

Correct Answer: D

Rationale: Elasticity refers to a material's ability to resist deformation and return to its original shape after stress is applied. It is the property that resists a change in shape. Density is the mass per unit volume of a substance. Mass is the amount of matter in an object, while inertia is the tendency of an object to resist changes in its state of motion. Viscosity, not mentioned in the question, is the resistance of a fluid to flow, not shape change.

Correct Answer: D

Rationale: The correct answer is the f orbital. Each f orbital can hold up to 2 electrons. Since there are 5 f orbitals, the total maximum number of electrons that can be accommodated in f orbitals is 10 (2 electrons per orbital x 5 orbitals = 10 electrons). Therefore, the f orbital can hold a maximum of 10 electrons. Choice A, s orbital, is incorrect because it can hold a maximum of 2 electrons. Choice B, p orbital, is incorrect because it can hold a maximum of 6 electrons (3 orbitals x 2 electrons per orbital = 6 electrons). Choice C, d orbital, is incorrect as it can hold a maximum of 10 electrons (5 orbitals x 2 electrons per orbital = 10 electrons), but the question asks for the type of orbital that can hold a maximum of 10 electrons, not the total number of electrons in d orbitals.

Correct Answer: C

Rationale: The correct answer is 'Mixing.' When substances are combined, a heterogeneous mixture is formed where the components are physically distinguishable. 'Dissolving' (Choice A) is the process of a solute becoming uniformly dispersed in a solvent to form a solution, not a heterogeneous mixture. 'Diluting' (Choice B) refers to reducing the concentration of a solute in a solution. 'Reacting' (Choice D) involves a chemical change where substances interact to form new products, rather than just physically mixing to form a heterogeneous mixture.

Correct Answer: B

Rationale: B) Commensalism: In commensalism, one organism benefits while the other is neither helped nor harmed. This is the relationship described in the question. The correct answer is Commensalism because it specifically fits the scenario where one organism benefits without affecting the other. A) Mutualism: In mutualism, both organisms involved benefit from the relationship. C) Parasitism: In parasitism, one organism benefits at the expense of the other organism, which is harmed. D) Predation: In predation, one organism (predator) kills and consumes another organism (prey) for food.