Nursing Elites

1. The number of protons in the nucleus of an atom determines its:

• A. Mass number
• B. Atomic number
• C. Isotope
• D. Valence electron count

Correct answer: B

Rationale: The atomic number (Z) equals the number of protons in the nucleus and uniquely identifies an element. Mass number (A) includes both protons and neutrons, isotopes have different neutron numbers, and valence electrons are involved in bonding, not atomic identity.

2. The muscular tube connecting the mouth to the stomach is lined with a mucous membrane. What is the main function of this mucous membrane?

• A. Secretion of digestive enzymes
• B. Absorption of nutrients
• C. Lubrication and protection
• D. Storage of bile

Correct answer: C

Rationale: The correct answer is C: Lubrication and protection. The mucous membrane lining the esophagus serves to provide lubrication for food as it travels from the mouth to the stomach, making it easier to swallow. Additionally, the mucous membrane protects the esophageal tissue from damage caused by the passage of food and liquids. This function is crucial in preventing irritation and inflammation of the esophagus, ensuring smooth and efficient digestion process. The mucous membrane does not secrete digestive enzymes (A), absorb nutrients (B), or store bile (D), as those functions are carried out by other digestive organs.

3. Bile, stored in the gallbladder, aids in the digestion of:

• A. Carbohydrates
• B. Proteins
• C. Fats
• D. Vitamins

Correct answer: C

Rationale: The correct answer is C: "Fats." Bile, produced by the liver and stored in the gallbladder, plays a crucial role in the digestion and absorption of fats. When you consume fatty foods, bile is released into the small intestine to help break down the fats into smaller droplets, making it easier for enzymes to digest them. This process allows the body to absorb essential fatty acids and fat-soluble vitamins. Carbohydrates are mainly digested by enzymes like amylase in the mouth and small intestine, while proteins are broken down by enzymes like pepsin and trypsin. Vitamins are not directly digested by bile but are absorbed along with fats in the small intestine. Therefore, the correct answer is C, as bile aids in the digestion of fats.

4. What is the term for the reaction between an acid and a base to produce water and a salt?

• A. Combustion
• B. Neutralization
• C. Oxidation
• D. Decomposition

Correct answer: b

Rationale: Neutralization is the reaction between an acid and a base to produce water and a salt. The other choices do not accurately describe neutralization.

5. How does the stability of an atom's nucleus influence its radioactive decay?

• A. Stable nuclei never undergo radioactive decay.
• B. Unstable nuclei are more likely to decay through various processes.
• C. Decay releases energy, making stable nuclei more prone to it.
• D. The element's position on the periodic table determines its decay rate.

Correct answer: B

Rationale: Unstable nuclei are more likely to decay through various processes. The stability of an atom's nucleus is a key factor in determining whether it will undergo radioactive decay. Unstable nuclei have an excess of either protons or neutrons, leading to an imbalance in the nucleus. To achieve a more stable configuration, these nuclei will undergo radioactive decay by emitting particles or energy. Stable nuclei, on the other hand, are less likely to undergo radioactive decay as they have a balanced number of protons and neutrons.

6. When ice melts, it undergoes a…

• A. Chemical change
• B. Physical change
• C. Nuclear change
• D. Radioactive decay

Correct answer: B

Rationale: Melting is a change in physical state, not a change in the chemical composition of the ice.

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