Nursing Elites

1. In a single displacement reaction, one element takes the place of another element in a compound. Which of the following is an example?

• A. 2H2 + O2 -> 2H2O
• B. Zn + 2HCl -> ZnCl2 + H2
• C. CaCO3 -> CaO + CO2
• D. CH4 + 2O2 -> CO2 + 2H2O

Correct answer: B

Rationale: Option B demonstrates a single displacement reaction where zinc (Zn) displaces hydrogen (H) in hydrochloric acid (HCl) to produce zinc chloride (ZnCl2) and hydrogen gas (H2). This reaction exemplifies the concept of one element (Zn) replacing another element (H) in a compound (HCl), which is characteristic of single displacement reactions. Choices A, C, and D do not involve a single element displacing another in a compound, making them incorrect. In choice A, hydrogen and oxygen combine to form water, which is not a single displacement reaction. In choice C, calcium carbonate decomposes into calcium oxide and carbon dioxide, not involving displacement of elements. In choice D, methane reacts with oxygen to form carbon dioxide and water, which is a combustion reaction, not a single displacement reaction.

2. What is the relationship between the wavelength (λ) and frequency (f) of a wave with a constant speed (v)?

• A. λ = v / f
• B. λ = f / v
• C. λ = vf
• D. λ is independent of f and v

Correct answer: A

Rationale: The relationship between wavelength (λ), frequency (f), and speed (v) of a wave is given by the formula λ = v / f. This formula is derived from the wave equation v = fλ, where v is the speed of the wave, f is the frequency, and λ is the wavelength. By rearranging the equation, we get λ = v / f, indicating that the wavelength is inversely proportional to the frequency when the speed of the wave is constant. Therefore, choice A, λ = v / f, correctly represents the relationship between wavelength and frequency when the speed of the wave is held constant. Choice B, λ = f / v, is incorrect because it represents an inverse relationship between wavelength and speed, which is not the case. Choice C, λ = vf, is incorrect as it implies a direct relationship between wavelength, frequency, and speed, which is not accurate. Choice D, λ is independent of f and v, is incorrect as both frequency and speed affect the wavelength of a wave, as shown by the correct formula λ = v / f.

3. Where is the cervix located?

• A. Top of the uterus
• B. Top of the ovaries
• C. Bottom of the vagina
• D. Bottom of the uterus

Correct answer: D

Rationale: The cervix is located at the bottom of the uterus, where it opens into the vagina. It serves as the passageway between the uterus and the vagina, playing a crucial role in childbirth and menstrual flow. Choice A ('Top of the uterus') is incorrect because the cervix is not located at the top of the uterus. Choice B ('Top of the ovaries') is incorrect as the cervix is not located near the ovaries. Choice C ('Bottom of the vagina') is incorrect as the cervix is not located at the bottom of the vagina, but rather at the bottom of the uterus.

4. In a scientific investigation, what is the first step?

• A. Analysis of results
• B. Drawing conclusions
• C. Formation of hypothesis
• D. Performing the experiment

Correct answer: C

Rationale: The correct answer is C: Formation of hypothesis. In a scientific investigation, forming a hypothesis is the initial step. A hypothesis is an educated guess or prediction based on existing knowledge and observations. It helps guide the experiment and provides a direction for the research process. Without a hypothesis, there is no specific aim or goal for the experiment. Choices A, B, and D are incorrect because they occur after the formation of a hypothesis. Analysis of results and drawing conclusions typically come after the experiment has been conducted, while performing the experiment is done to test the hypothesis formed at the beginning of the investigation.

5. At what stage is urine formed in the kidney?

• A. After fluid reaches the bladder.
• B. When fluid fills the collecting duct.
• C. Before blood enters the glomerulus.
• D. During fluid transport to the urethra.

Correct answer: B

Rationale: Urine is formed when fluid fills the collecting duct in the kidney. The collecting duct is where the final concentration of urine occurs after the filtration process in the nephron. Choice A is incorrect because urine formation happens before fluid reaches the bladder. Choice C is incorrect because urine formation occurs after blood has been filtered in the glomerulus. Choice D is incorrect because urine formation happens before fluid is transported to the urethra for elimination.

Similar Questions