HESI A2
HESI A2 Chemistry
1. If fifty-six kilograms of a radioactive substance has a half-life of 12 days, how many days will it take the substance to decay naturally to only 7 kilograms?
- A. 8
- B. 12
- C. 36
- D. 48
Correct answer: C
Rationale: To decay from 56 kg to 7 kg, the substance needs to go through 3 half-lives (56 kg ÷ 2 ÷ 2 ÷ 2 = 7 kg). Since each half-life is 12 days, the total time required is 12 days per half-life x 3 half-lives = 36 days. Choice A is incorrect because it does not consider the concept of half-lives. Choice B is incorrect because it represents the duration of a single half-life, not the total time required for the decay. Choice D is incorrect as it does not account for the multiple half-lives needed for the substance to decay from 56 kg to 7 kg.
2. How many different types of tissues are there in the human body?
- A. four
- B. six
- C. eight
- D. ten
Correct answer: A
Rationale: There are four major types of tissues in the human body: epithelial, connective, muscle, and nervous tissues. Epithelial tissue covers body surfaces, connective tissue supports and binds other tissues together, muscle tissue enables movement, and nervous tissue allows for communication between different parts of the body. Choices B, C, and D are incorrect because the human body has four main types of tissues, not six, eight, or ten.
3. How does insomnia affect intellectual abilities?
- A. Causes a deficit in memory, concentration, and attention.
- B. Improves mental alertness.
- C. Boosts concentration levels.
- D. Has no effect on intellectual abilities.
Correct answer: A
Rationale: Insomnia affects intellectual abilities by causing a deficit in memory, concentration, and attention. The passage highlights that lack of sleep impacts memory, attention, and concentration, leading to feelings of irritation or depression. Therefore, choice A is correct. Choices B, C, and D are incorrect because they do not align with the negative impact insomnia has on intellectual abilities as described in the passage.
4. What does the word 'obligatory' mean in the context of the passage on Daylight Savings Time?
- A. Approved.
- B. Sparse.
- C. Requisite.
- D. Aberrant.
Correct answer: C
Rationale: In the passage, Daylight Savings Time is presented as something that must be done by law, making it a requirement or something obligatory. 'Requisite' fits this meaning. 'Approved' (choice A) does not convey the sense of necessity as 'obligatory' does. 'Sparse' (choice B) means thinly dispersed and does not relate to the context. 'Aberrant' (choice D) means deviating from the norm, which is not applicable in this context.
5. An inability to be lucid in the early morning means the person is unable to behave in which way?
- A. Coherent
- B. Speculative
- C. Furtive
- D. Animated
Correct answer: A
Rationale: An inability to be lucid in the early morning means the person is unable to behave in a coherent way. Lucidity refers to clarity of thought and coherence in one's behavior or speech. If someone is not lucid, they may be confused, disoriented, or unable to express themselves clearly. Therefore, the correct choice is A. Coherent. Choices B, C, and D are incorrect because being unable to be lucid does not necessarily mean the person is behaving in a speculative, furtive, or animated way.
Similar Questions
Access More Features
HESI A2 Basic
$49/ 30 days
- 3,000 Questions with answers
- 30 days access
HESI A2 Premium
$99/ 90 days
- Actual HESI A2 Questions
- 3,000 questions with answers
- 90 days access