Nursing Elites

1. The defining characteristic of an element is determined by the number of:

• A. Neutrons in its nucleus
• B. Electrons surrounding the nucleus
• C. Protons in its nucleus
• D. All of the above

Correct answer: C

Rationale: The correct answer is C: 'Protons in its nucleus.' An element is defined by the number of protons in its nucleus, known as the atomic number. This number determines the element's identity and its placement on the periodic table. Neutrons and electrons play important roles in an atom, but they do not define the element itself. Neutrons contribute to the atom's mass, while electrons are involved in chemical reactions and bonding. Therefore, the number of protons is the defining characteristic of an element.

2. Which property of a wave determines its energy?

• A. Wavelength
• B. Amplitude
• C. Frequency
• D. Velocity

Correct answer: b

Rationale: Amplitude is directly related to the energy carried by a wave - higher amplitudes correspond to higher energy waves.

3. What is the absolute value of -7?

• A. 49
• B. 17
• C. 7
• D. 14

Correct answer: A

Rationale: Absolute value refers to the non-negative distance of a number from zero. Regardless of being positive or negative, 7 is its distance from zero.

4. What is the term for the involuntary muscle contractions that move food through the digestive tract?

• A. Segmentation
• B. Peristalsis
• C. Chyme
• D. Emulsification

Correct answer: B

Rationale: The correct answer is B: Peristalsis. Peristalsis is the term used to describe the involuntary muscle contractions that help move food through the digestive tract. These rhythmic contractions occur in the smooth muscles of the digestive system and help propel food and other substances like chyme through the esophagus, stomach, and intestines. Segmentation, choice A, refers to the mixing movements in the intestines that aid in digestion but do not move food along the tract. Chyme, choice C, is the semi-fluid mass of partially digested food that moves from the stomach to the small intestine. Emulsification, choice D, is the process of breaking down fats into smaller droplets to aid in digestion, but it is not directly related to the movement of food through the digestive tract.

5. 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.

6. In the reaction 2Na + 2H2O → 2NaOH + H2, what is the limiting reactant when 3 moles of sodium react with 2 moles of water?

• A. Na
• B. H2O
• C. NaOH
• D. H2

Correct answer: a

Rationale: Sodium is the limiting reactant because it runs out first in a 1:1 ratio with water.

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