Nursing Elites

1. In which state of matter are particles packed tightly together in a fixed position?

• A. Liquid
• B. Solid
• C. Gas
• D. Plasma

Correct answer: B

Rationale: In a 'solid' state, particles are tightly packed in fixed positions, maintaining a definite shape and volume. This arrangement allows solids to maintain a rigid structure. Liquids have particles that are close together but can move past each other, giving them the ability to flow and take the shape of their container. Gases have particles that are far apart and move freely, leading to their ability to expand to fill any container. Plasma is an ionized gas where particles have high energy levels and are not packed tightly together, making it an uncommon state of matter on Earth.

2. Radioactive isotopes are frequently used in medicine. What kind of half-life would a medical isotope probably have?

• A. Seconds-long
• B. Days-long
• C. Years-long
• D. Many years long

Correct answer: B

Rationale: Medical isotopes used in diagnosis and treatment need to have a relatively short half-life to minimize radiation exposure to patients. If the half-life were too long (such as many years) or even years-long, the radiation would persist for too long and could be harmful to the patient. Seconds-long half-lives would not provide enough time for the isotope to be effective. Days-long half-lives strike a balance between providing enough time for the isotope to be used effectively and minimizing radiation exposure.

3. What can stop the penetration of gamma radiation?

• A. Aluminum foil
• B. Glass
• C. Several feet of concrete
• D. Piece of paper

Correct answer: C

Rationale: Gamma radiation is highly penetrative and requires dense materials to block it effectively. While aluminum foil and glass are not sufficient to stop gamma radiation, several feet of concrete is needed due to its high density and ability to absorb gamma radiation effectively. A piece of paper is too thin and lacks the density required to block gamma radiation, making it an ineffective shield.

4. Which substance shows a decrease in solubility in water with an increase in temperature?

• A. NaCl
• B. O
• C. KI
• D. CaCl

Correct answer: C

Rationale: Potassium iodide (KI) shows a decrease in solubility in water with an increase in temperature. This is due to the dissolution of KI in water being an endothermic process. When the temperature rises, the equilibrium shifts toward the solid state, leading to a decrease in solubility. Therefore, as the temperature increases, KI becomes less soluble in water. Choice A (NaCl) and Choice D (CaCl) do not exhibit a decrease in solubility with an increase in temperature. NaCl and CaCl are generally more soluble in water at higher temperatures. Choice B (Oxygen) is a gas and not typically considered in solubility discussions involving solids or liquids dissolving in water.

5. What is an alloy in which another metal is dissolved in mercury (Hg) called?

• A. Electrum
• B. Amalgam
• C. Solder
• D. Bronze

Correct answer: B

Rationale: An amalgam is a type of alloy where another metal is dissolved in mercury (Hg). This process forms a unique mixture that has various applications in dentistry, chemistry, and other fields. Electrum is a natural alloy of gold and silver, solder is a metal alloy used to join other metals together, and bronze is a copper-tin alloy. Therefore, the correct answer is B - Amalgam.

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