Nursing Elites

1. What does the sum of protons and neutrons in an element represent?

• A. Atomic number
• B. Mass number
• C. Atomic mass
• D. Neutron number

Correct answer: B

Rationale: The sum of protons and neutrons in an element is known as the mass number. The mass number is an important concept in chemistry as it represents the total number of nucleons (protons and neutrons) in an atom's nucleus. It is different from the atomic number, which represents the number of protons in an atom. The atomic mass is the average mass of an element's isotopes, taking into account the abundance of each isotope. Neutron number, on the other hand, specifically refers to the number of neutrons in an atom's nucleus. Therefore, the correct answer is B, mass number.

2. What is the correct formula for calcium carbonate?

• A. CaSO₃
• B. CaCO₃
• C. Ca(OH)₂
• D. CH₃OH

Correct answer: B

Rationale: The correct formula for calcium carbonate is CaCO₃, which consists of one calcium (Ca) atom, one carbon (C) atom, and three oxygen (O) atoms. Therefore, choice B, CaCO₃, is the accurate formula for calcium carbonate. Choices A, C, and D do not represent the correct formula for calcium carbonate. Choice A, CaSO₃, is calcium sulfite, not calcium carbonate. Choice C, Ca(OH)₂, is calcium hydroxide, and choice D, CH₃OH, is methanol, none of which are correct formulas for calcium carbonate.

3. What is the name for the horizontal rows of the periodic table?

• A. groups
• B. periods
• C. families
• D. sets

Correct answer: B

Rationale: In the periodic table, 'periods' are the horizontal rows. Each period corresponds to the energy level occupied by the elements in that row. The other terms mentioned, such as groups, families, and sets, are not used to describe the horizontal rows but rather refer to different aspects of the periodic table organization. 'Groups' are the vertical columns, 'families' are groups of elements with similar properties, and 'sets' is a more generic term not specifically used in the context of the periodic table.

4. What are the two types of chemical bonding?

• A. Covalent & hydrogen
• B. Ionic & covalent
• C. Ionic & hydrogen
• D. Covalent & metallic

Correct answer: B

Rationale: The correct answer is B: Ionic & covalent. Ionic bonding involves the transfer of electrons between atoms, resulting in the formation of positive and negative ions attracted to each other. Covalent bonding involves the sharing of electrons between atoms to achieve a stable electron configuration. Choice A is incorrect as hydrogen bonding is a type of intermolecular force, not a primary type of chemical bonding. Choice C is incorrect as hydrogen bonding is not a primary type of chemical bonding. Choice D is incorrect as metallic bonding involves the sharing of electrons in a 'sea of electrons' within a metal lattice, not covalent bonding.

5. What is the correct name of AgNO₃?

• A. Argent nitrous
• B. Argent oxide
• C. Silver nitrite
• D. Silver nitrate

Correct answer: D

Rationale: The correct name for AgNO₃ is silver nitrate. In chemical nomenclature, the element symbol Ag represents silver, and the polyatomic ion NO₃ is known as nitrate. Therefore, when the silver ion (Ag⁺) combines with the nitrate ion (NO₃⁻), the resulting compound is named silver nitrate (AgNO₃). Choices A, B, and C are incorrect because they do not accurately represent the composition of AgNO₃. Argent nitrous (Choice A) and Argent oxide (Choice B) do not reflect the correct anion, and Silver nitrite (Choice C) uses a different anion altogether.

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