which of the following elements is a halogen
Logo

Nursing Elites

HESI A2

HESI A2 Chemistry Questions

1. Which of the following elements is a halogen?

Correct answer: B

Rationale: The correct answer is 'Fluorine' (Choice B) as it is a halogen. Halogens are a group of elements that include fluorine, chlorine, bromine, iodine, and astatine. They are highly reactive nonmetals located in Group 17 of the periodic table. Oxygen (Choice A) is a nonmetal but not a halogen. Sodium (Choice C) is a metal, and Carbon (Choice D) is a nonmetal, neither of which belong to the halogen group.

2. Choose the two bases that have two carbon rings:

Correct answer: A

Rationale: Adenine and guanine have two carbon rings and are known as purines. These bases are found in nucleic acids such as DNA and RNA. Adenine (option A) and guanine (option D) are the correct choices as they both have two carbon rings in their molecular structure. Cytosine (option B) and thymine (option C) have a single carbon ring each, making them incorrect choices for bases with two carbon rings.

3. How many electrons are shared in a single covalent bond?

Correct answer: B

Rationale: The correct answer is B: '2'. In a single covalent bond, two electrons are shared between two atoms. Each atom contributes one electron to form the bond, resulting in the sharing of a total of two electrons. Choice A is incorrect because a single covalent bond involves the sharing of two electrons, not one. Choices C and D are incorrect as they do not represent the correct number of electrons shared in a single covalent bond.

4. Which animal has an open transport system?

Correct answer: B

Rationale: The correct answer is B: Earthworm. Earthworms have an open circulatory system, meaning their blood and interstitial fluid are not enclosed in blood vessels. Instead, the blood flows freely within the body cavity, allowing for direct exchange of nutrients and waste products with surrounding tissues. This lack of a closed transport system is a characteristic feature of earthworms. Choices A, C, and D are incorrect because grasshoppers, dolphins, and chickens have closed circulatory systems where the blood is enclosed within blood vessels, unlike earthworms.

5. Another word for UNDER OBSERVATION is?

Correct answer: C

Rationale: The correct answer is C, 'Surveillance,' which means 'under observation.' 'Cognition' (A) refers to mental processes, 'Isolation' (B) means being separated from others, and 'Assessment' (D) is the evaluation of something, none of which directly relate to being observed.

Similar Questions

He ate four pieces of fried chicken at dinner, and _____ vegetables.
Which word is not spelled correctly in the context of the following sentence? Nothing can be more delightful than a late-night swim in the reservoir.
If electrons are shared equally in a covalent bond, the bond is classified as what?
Select the word that makes the following sentence grammatically correct. The nursing staff ___________ to serve their patients well.
An object with a charge of 4 μC is placed 1 meter from another object with a charge of 2 μC. What is the magnitude of the resulting force between the objects?

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

Other Courses