Nursing Elites

1. When is a solution formed?

• A. One substance dissolves in another
• B. Two or more substances react chemically
• C. A solid changes to a liquid
• D. None of the above

Correct answer: A

Rationale: A solution is formed when one substance dissolves in another. This process creates a homogeneous mixture where the solute is dispersed in the solvent, resulting in a uniform composition throughout the mixture. Choice B is incorrect because chemical reactions involve the transformation of substances into new compounds, not the formation of solutions. Choice C is incorrect as it describes a physical change from a solid to a liquid, not the formation of a solution. Choice D is incorrect as one substance dissolving in another is the defining characteristic of a solution.

2. Which property of a substance refers to its ability to undergo a chemical change and form new substances?

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

Correct answer: C

Rationale: Reactivity is the property of a substance that describes its ability to undergo a chemical change and form new substances through chemical reactions. Density, mass, and volume are physical properties of a substance and do not directly relate to its ability to undergo chemical changes. Density is the mass of a substance per unit volume, mass is the amount of matter present, and volume is the amount of space occupied by the substance. Reactivity specifically deals with how likely a substance is to engage in chemical reactions. Therefore, the correct answer is C - Reactivity.

3. What is the shape of the DNA molecule?

• A. Linear
• B. Circular
• C. Double helix
• D. Straight chain

Correct answer: C

Rationale: The correct answer is C: Double helix. The shape of the DNA molecule is a double helix, a structure first described by James Watson and Francis Crick in 1953. This shape consists of two strands twisted around each other in a spiral. The double helix structure allows DNA to be compactly stored within the cell nucleus and provides stability to the molecule. Options (A) Linear, (B) Circular, and (D) Straight chain are incorrect as they do not accurately represent the shape of the DNA molecule. DNA is not linear but rather forms a twisted double helix; it is not circular like a ring but has a spiral structure, and it is not a straight chain but a twisted ladder-like structure.

4. What is the process of cells becoming specialized to perform specific functions called?

• A. Cell division
• B. Cell differentiation
• C. Cell growth
• D. Cell regeneration

Correct answer: B

Rationale: Cell differentiation is the process by which cells become specialized to perform specific functions. During differentiation, cells acquire specific structures and functions that allow them to carry out particular roles in the body. Cell division refers to the process by which a parent cell divides into two or more daughter cells. Cell growth is the process by which cells increase in size and number. Cell regeneration is the process by which new cells are produced to replace damaged or lost cells in an organism. Therefore, in this context, the process of cells becoming specialized to perform specific functions is best described as cell differentiation.

5. Which form of energy is associated with the motion of an object?

• A. Kinetic energy
• B. Potential energy
• C. Thermal energy
• D. Electrical energy

Correct answer: A

Rationale: Kinetic energy is the form of energy associated with the motion of an object. When an object is in motion, it possesses kinetic energy due to its movement. Potential energy, on the other hand, is stored energy that an object has due to its position or condition. Thermal energy is related to heat, while electrical energy is associated with the flow of electric charge. In this case, the correct answer is kinetic energy as it directly correlates with the motion of an object.

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