Nursing Elites

1. What is the pH of a solution with a hydrogen ion concentration of \(1 \times 10^{-9}\) M?

• A. 5
• B. 7
• C. 9
• D. 11

Correct answer: c

Rationale: The pH is calculated as the negative logarithm (base 10) of the hydrogen ion concentration. In this case, \(-\log(1 \times 10^{-9}) = 9\).

2. What is the role of DNA in evolution?

• A. It stores genetic information that can be passed on to offspring
• B. It allows for mutations that can introduce new variations
• C. It regulates the expression of genes that influence traits
• D. All of the above

Correct answer: D

Rationale: Rationale: A) DNA stores genetic information that is passed on from parents to offspring through the process of reproduction. This genetic information contains instructions for the development and functioning of an organism. B) DNA can undergo mutations, which are changes in the genetic sequence. These mutations can introduce new variations in the DNA, leading to genetic diversity within a population. C) DNA plays a crucial role in regulating the expression of genes. Gene expression determines which proteins are produced in an organism, influencing its traits and characteristics. D) Therefore, DNA is involved in all of the above processes, making it a key factor in evolution by driving genetic variation, inheritance, and gene expression.

3. What is the main function of the epiglottis?

• A. To store bile
• B. To absorb nutrients
• C. To prevent food from entering the trachea
• D. To produce digestive enzymes

Correct answer: C

Rationale: Rationale: The epiglottis is a flap of cartilage located at the base of the tongue that covers the opening of the trachea during swallowing to prevent food and liquids from entering the airway. This action helps direct food and liquids into the esophagus, which leads to the stomach for digestion, while also protecting the respiratory system from potential blockages that could lead to choking or aspiration pneumonia. Options A, B, and D are incorrect as the epiglottis is not involved in storing bile, absorbing nutrients, or producing digestive enzymes.

4. What is the relationship between work and the displacement of an object?

• A. Work depends only on the force applied, not displacement
• B. Work is directly proportional to displacement
• C. Work is inversely proportional to displacement
• D. Work is unrelated to displacement

Correct answer:

Rationale: Work done is directly proportional to the displacement of an object in the direction of the force applied.

5. An Egyptian model pyramid has a square base side length of 10cm and a height of 8cm. What is its volume?

• A. 20 cu cm
• B. 40 cu cm
• C. 80 cu cm
• D. 160 cu cm

Correct answer: D

Rationale: Use the formula for volume of a pyramid: (1/3) * base area * height. Calculate the base area (10cm * 10cm = 100 sq cm) and substitute: (1/3) * 100 sq cm * 8cm = 80 cu cm.

6. A balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride is:

• A. Na + Cl2 -> NaCl
• B. 2Na + Cl2 -> 2NaCl
• C. Na2 + Cl -> 2NaCl
• D. Na + 2Cl -> NaCl2

Correct answer: A

Rationale: The correct balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride is '2Na + Cl2 -> 2NaCl'. This equation is balanced as it shows that 2 atoms of sodium react with 1 molecule of chlorine gas to produce 2 molecules of sodium chloride. Option A 'Na + Cl2 -> NaCl' is incorrect as it does not balance the number of atoms on both sides of the equation. It only shows 1 atom of sodium reacting with 1 molecule of chlorine, which is not a balanced representation of the chemical reaction. Therefore, option B is the correct choice for this question.

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