HESI A2
Chemistry HESI A2 Quizlet
1. What term is used to describe the emission of particles from an unstable nucleus?
- A. Radioactivity
- B. Radiation
- C. Decay
- D. Fusion
Correct answer: A
Rationale: Radioactivity is the term used to describe the emission of particles from an unstable nucleus. When a nucleus is unstable, it undergoes radioactive decay by emitting particles such as alpha or beta particles. This process releases energy and transforms the unstable nucleus into a more stable configuration. Choice B, 'Radiation,' is a broad term that encompasses various forms of energy emitted from a source; it is not specific to the emission from an unstable nucleus. Choice C, 'Decay,' is closely related but doesn't specifically indicate the emission of particles from an unstable nucleus. Choice D, 'Fusion,' refers to the process of combining nuclei to form a heavier nucleus, not the emission of particles from an unstable nucleus.
2. What is the correct name of MgO?
- A. Manganese oxide
- B. Magnesium oxide
- C. Magnesium oxate
- D. Magnesium hydroxide
Correct answer: B
Rationale: The correct name of MgO is Magnesium oxide. Mg represents the chemical symbol for magnesium, and O represents the chemical symbol for oxygen. When these elements combine, they form magnesium oxide. Option A, Manganese oxide, is incorrect as it refers to a compound of manganese and oxygen, not magnesium. Option C, Magnesium oxate, is not a valid chemical compound name. Option D, Magnesium hydroxide, refers to a different compound consisting of magnesium, oxygen, and hydrogen.
3. What is another name for aqueous HI?
- A. hydroiodic acid
- B. hydrogen monoiodide
- C. hydrogen iodide
- D. hydriodic acid
Correct answer: D
Rationale: The correct name for aqueous HI is 'hydriodic acid.' When hydrogen iodide (HI) dissolves in water, it forms hydriodic acid. Therefore, 'hydriodic acid' is the appropriate term for aqueous HI. Choice A, 'hydroiodic acid,' is incorrect as it does not reflect the nature of the compound in the aqueous state. Choice B, 'hydrogen monoiodide,' is not a widely recognized term for this compound. Choice C, 'hydrogen iodide,' is the name for HI in the gaseous state, not when it's dissolved in water.
4. Which substance forms hydroxide ions when placed in water?
- A. Lemon juice
- B. Battery acid
- C. Vinegar
- D. Lye
Correct answer: D
Rationale: The correct answer is D, lye. Lye, also known as sodium hydroxide (NaOH), is a strong base that forms hydroxide ions (OH-) when placed in water. When lye dissolves in water, it dissociates into sodium ions (Na+) and hydroxide ions, making it an alkaline substance. Lemon juice, battery acid, and vinegar do not form hydroxide ions when placed in water. Lemon juice contains citric acid, battery acid contains sulfuric acid, and vinegar contains acetic acid, none of which produce hydroxide ions when dissolved in water.
5. Which of these intermolecular forces might represent attraction between atoms of a noble gas?
- A. Dipole-dipole interaction
- B. London dispersion force
- C. Keesom interaction
- D. Hydrogen bonding
Correct answer: B
Rationale: Noble gases are non-polar molecules without a permanent dipole moment. The only intermolecular force applicable to noble gases is the London dispersion force, also known as Van der Waals forces. This force is a temporary attractive force resulting from the formation of temporary dipoles in non-polar molecules. Dipole-dipole interactions, Keesom interactions, and hydrogen bonding involve significant dipoles or hydrogen atoms bonded to electronegative atoms, which do not apply to noble gases.
Similar Questions
Access More Features
HESI A2 Basic
$99/ 30 days
- 3,000 Questions with answers
- 30 days access
HESI A2 Premium
$149.99/ 90 days
- Actual HESI A2 Questions
- 3,000 questions with answers
- 90 days access