Nursing Elites

1. What type of lens is thinner at the center than at the edges and causes light rays to diverge?

• A. Convex lens
• B. Concave lens
• C. Diverging lens
• D. Plano-convex lens

Correct answer: B

Rationale: A concave lens is thinner at the center than at the edges, causing light rays to diverge when passing through it. This type of lens is also known as a diverging lens because it causes light rays to spread out. Concave lenses are used in various optical devices to correct vision problems and in scientific instruments to diverge light rays for specific purposes. The other choices are incorrect. A convex lens is thicker at the center and converges light rays, while a plano-convex lens has one flat surface and one convex surface, converging light. Diverging lens is a general term that can refer to concave or plano-concave lenses, but in this context, the specific type being referred to is a concave lens.

2. Which of the following colligative properties refers to the elevation of the boiling point of a solution?

• A. Freezing point depression
• B. Vapor pressure lowering
• C. Osmotic pressure
• D. Boiling point elevation

Correct answer: D

Rationale: The correct answer is D, 'Boiling point elevation.' Boiling point elevation is a colligative property that describes the increase in the boiling point of a solvent when a non-volatile solute is added to it. This occurs because the presence of solute particles in the solvent lowers the vapor pressure of the solution, requiring a higher temperature to reach the same vapor pressure as the pure solvent. Choices A, B, and C are incorrect. Freezing point depression refers to the lowering of the freezing point of a solution, vapor pressure lowering is the reduction in vapor pressure due to the presence of solute particles, and osmotic pressure is the pressure required to prevent the flow of solvent molecules across a semipermeable membrane in osmosis.

3. Which element is used in fire extinguishers to smother flames by displacing oxygen?

• A. Nitrogen
• B. Carbon dioxide
• C. Helium
• D. Argon

Correct answer: B

Rationale: Carbon dioxide is the correct answer. It is used in fire extinguishers because it displaces oxygen, which is necessary for combustion. When carbon dioxide is released onto a fire, it reduces the oxygen concentration around the flames, effectively smothering the fire. This disruption of oxygen availability interrupts the chemical reaction that sustains the fire. Nitrogen (Choice A), helium (Choice C), and argon (Choice D) are not typically used in fire extinguishers for smothering flames by displacing oxygen. Nitrogen is an inert gas that can displace oxygen but is not as effective as carbon dioxide in fire suppression.

4. Which group of elements is known for their vibrant colors and is commonly used in fireworks?

• A. Noble gases
• B. Alkali metals
• C. Halogens
• D. Transition metals

Correct answer: D

Rationale: The correct answer is D: Transition metals. Transition metals are known for their vibrant colors and are commonly used in fireworks due to their ability to emit specific colors of light. The diverse electronic configurations of transition metals allow them to produce a variety of hues, making them ideal for creating colorful displays in fireworks. Choice A, Noble gases, do not typically produce vibrant colors in fireworks as they are colorless and odorless gases. Choice B, Alkali metals, are not known for their colorful displays in fireworks. Choice C, Halogens, can produce colors in fireworks, but they are not as commonly used for their vibrant hues compared to transition metals.

5. Which bone is the longest in the human body?

• A. Femur (Thigh bone)
• B. Humerus (Upper arm bone)
• C. Tibia (Shin bone)
• D. Scapula (Shoulder blade)

Correct answer: A

Rationale: The correct answer is the femur (thigh bone) as it is the longest bone in the human body, extending from the hip to the knee. It plays a vital role in supporting the body's weight and enabling movement. The humerus is located in the upper arm and is not as long as the femur. The tibia is the shin bone and is shorter than the femur. The scapula is the shoulder blade and is not the longest bone in the body, making it an incorrect choice.

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