Nursing Elites

1. Which of the following is an example of a chemical change?

• A. Dissolving sugar in water
• B. Boiling water
• C. Rusting iron
• D. Crushing ice

Correct answer: C

Rationale: Rusting iron is an example of a chemical change because it involves a chemical reaction where iron reacts with oxygen in the presence of water to form iron oxide (rust). This reaction results in a change in the chemical composition of the iron, unlike dissolving sugar in water, boiling water, or crushing ice, which are physical changes. Dissolving sugar in water is a physical change as sugar molecules remain unchanged but disperse in water. Boiling water is also a physical change as water changes its state from liquid to gas due to heat. Crushing ice is a physical change as the solid ice changes its physical form without altering its chemical composition.

2. What property of a substance measures the amount of matter per unit volume?

• A. Mass
• B. Weight
• C. Density
• D. Volume

Correct answer: C

Rationale: Density is the property of a substance that measures the amount of matter per unit volume. It is calculated by dividing the mass of an object by its volume. 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. Therefore, in this context, density is the correct answer as it specifically relates to the concentration of matter within a given volume.

3. How are the bones of the skull classified?

• A. Long bones
• B. Short bones
• C. Flat bones
• D. Irregular bones

Correct answer: C

Rationale: The bones of the skull are classified as flat bones. Flat bones are thin, flattened, and usually curved bones that provide protection to underlying organs and have a large surface area for muscle attachment. The skull bones fit this description as they protect the brain and have a broad surface for muscle attachment. Choice A (Long bones), B (Short bones), and D (Irregular bones) are incorrect classifications. Long bones are typically found in the extremities like the arms and legs, short bones are cube-shaped like the wrist and ankle bones, and irregular bones have complex shapes like the vertebrae. These classifications do not describe the bones of the skull, which are predominantly flat bones.

4. Which type of tissue protects the respiratory system's trachea?

• A. Bone
• B. Cartilage
• C. Collagen
• D. Keratin

Correct answer: B

Rationale: Cartilage is the correct answer as it provides flexible support and protection in the trachea. Cartilage is specifically designed to maintain the trachea's shape and prevent it from collapsing during breathing. Bone is a rigid tissue, not found in the trachea, and would not provide the necessary flexibility for breathing. Collagen is a structural protein but does not offer the same support and flexibility as cartilage in this context. Keratin is a protein that forms structures like hair and nails, and it is not present in the trachea to provide protection.

5. An object is thrown upwards and reaches a maximum height. Which of the following statements is TRUE about its velocity and acceleration at the peak?

• A. Velocity is zero and acceleration is maximum upwards.
• B. Velocity is maximum and acceleration is zero.
• C. Velocity is maximum and acceleration is maximum upwards.
• D. Velocity is zero and acceleration is maximum downwards.

Correct answer: A

Rationale: At the peak of the object's motion, its velocity is zero because it momentarily stops before changing direction and starts to fall back down. The acceleration at the peak is maximum upwards as gravity is acting against the object's motion, slowing it down until it stops momentarily. Choice A is correct because at the peak, the object's velocity is zero, and the acceleration is maximum upwards. Choice B is incorrect because the velocity is not maximum but zero at the peak. Choice C is incorrect as both velocity and acceleration are not maximum at the peak. Choice D is incorrect as the acceleration at the peak is upwards, opposing the object's motion, not downwards.

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