TEAS 7 science practice

Correct Answer: C

Rationale: Density is the measure of the mass of a substance per unit volume and is commonly expressed in kilograms per cubic meter. Mass refers to the amount of matter in an object, weight is the force of gravity acting on an object, and volume is the amount of space an object occupies. In this context, density is the correct term for expressing the measure of mass per unit volume, making it the most appropriate choice among the options provided.

Correct Answer: C

Rationale: The main function of the urinary system is to maintain the body's acid-base balance. This is achieved by regulating the levels of electrolytes and water in the body. The kidneys filter waste products from the blood to form urine, which helps to regulate the pH balance. Choice A, transporting oxygen, is primarily the function of the respiratory system. Choice B, fighting off infections, is a function of the immune system. Therefore, the correct answer is maintaining acid-base balance.

Correct Answer: B

Rationale: The correct answer is the reticular layer. This layer is the outermost layer of the dermis that contains abundant collagen and elastin fibers, providing elasticity to the skin. The papillary layer is located beneath the epidermis and is responsible for supplying nutrients to the epidermis, not the outermost layer. The stratum basale is the deepest layer of the epidermis where new skin cells are produced, not part of the dermis. The stratum corneum is the outermost layer of the epidermis composed of dead skin cells, not a layer of the dermis.

Correct Answer: B

Rationale: In the given redox reaction, I⁻ is gaining electrons to form I₂, which means I⁻ is being reduced (undergoing reduction). On the other hand, Cr₂O₇�⁻ is losing electrons to form Cr�⁺, indicating that Cr₂O₇�⁻ is being oxidized (undergoing oxidation). Therefore, I⁻ is the reducing agent and Cr₂O₇�⁻ is the oxidizing agent. Choice A is incorrect because I⁻ is being reduced, not oxidized. Choice C is incorrect as both species cannot be oxidized in the same reaction. Choice D is incorrect as both species cannot be reduced in the same reaction.

Correct Answer: B

Rationale: The correct term for the process of a gas changing directly into a solid is deposition. During deposition, gas particles lose energy and transition directly into the solid state without passing through the liquid phase. Sublimation, on the other hand, is the process in which a solid changes directly into a gas without going through the liquid phase. Condensation is the process where gas changes into a liquid state. Evaporation, on the contrary, is the conversion of a liquid to a gas. Therefore, the correct answer is B, deposition.