Nursing Elites

1. Balance the chemical equation: C4H10 + O2 → CO2 + H2O. What is the coefficient for oxygen?

• A. 5
• B. 6
• C. 7
• D. 8

Correct answer: B

Rationale: To balance the chemical equation, we need to ensure that the number of each type of atom is the same on both sides of the equation. In this case, there are 10 oxygen atoms on the right side (5 in CO2 and 5 in H2O). To balance this, we need to add a coefficient of 6 in front of O2 on the left side, resulting in 6 O2 molecules. This change will give us a total of 12 oxygen atoms on both sides, making the equation balanced. Choice A (5) is incorrect because it does not account for all the oxygen atoms present in the products. Choices C (7) and D (8) are incorrect as they would result in an imbalance in the number of oxygen atoms on both sides of the equation.

2. Which of the following is NOT a mechanism of evolution?

• A. Natural selection
• B. Genetic drift
• C. Lamarckism
• D. Mutation

Correct answer: C

Rationale: A) Natural selection is a mechanism of evolution where individuals with advantageous traits are more likely to survive and reproduce, passing on those traits to the next generation. B) Genetic drift is a mechanism of evolution that occurs due to random changes in allele frequencies in a population. C) Lamarckism, also known as the inheritance of acquired characteristics, is a discredited theory that suggests organisms can pass on traits acquired during their lifetime to their offspring. This mechanism has been largely rejected by the scientific community. D) Mutation is a mechanism of evolution that introduces new genetic variation into a population, which can lead to the emergence of new traits and adaptations over time.

3. What is the structural and functional unit of the kidney responsible for filtering blood?

• A. Nephron
• B. Ureter
• C. Urethra
• D. Bladder

Correct answer: A

Rationale: The nephron is the correct answer. It is the structural and functional unit of the kidney responsible for filtering blood. The nephron consists of a renal corpuscle (glomerulus and Bowman's capsule) and a renal tubule. Within the nephron, blood is filtered to form urine, which is then carried to the ureter for excretion from the body. Choices B, C, and D are incorrect because the ureter, urethra, and bladder are not involved in the filtration of blood in the kidney. Instead, they are parts of the urinary system responsible for transporting and storing urine.

4. Why are elements in Group 18 (Noble gases) generally unreactive?

• A. They have high atomic masses
• B. They lack valence electrons
• C. Their outermost electron shells are completely filled
• D. They exist as single atoms, not molecules

Correct answer: C

Rationale: Elements in Group 18 (Noble gases) are generally unreactive because their outermost electron shells are completely filled. This results in high stability and low reactivity since they have achieved a full valence shell configuration, making them less likely to gain, lose, or share electrons with other atoms. The full valence shell configuration leads to a minimal tendency for these elements to form chemical bonds, hence exhibiting low reactivity. Choices A, B, and D are incorrect because high atomic masses, lack of valence electrons, and existing as single atoms do not directly contribute to the unreactivity of noble gases. It is the full valence shell configuration that is the primary reason for their inert nature.

5. Which of the following macromolecules will always contain nitrogen?

• A. Fatty acids
• B. Proteins
• C. Lipids
• D. Carbohydrates

Correct answer: B

Rationale: The correct answer is B: Proteins. Proteins are the only macromolecules that always contain nitrogen in their amino acid structure. Nitrogen is a key element found in the amino groups of amino acids, which are the building blocks of proteins. Fatty acids (Choice A), lipids (Choice C), and carbohydrates (Choice D) do not always contain nitrogen in their structure. Fatty acids are composed of long hydrocarbon chains and do not contain nitrogen. Lipids consist mainly of carbon, hydrogen, and oxygen, with some classes of lipids containing phosphorus but not nitrogen. Carbohydrates are made up of carbon, hydrogen, and oxygen, forming structures like sugars and starches, but they do not contain nitrogen.

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