which elements are generally involved in hydrogen bonding

HESI A2

Chemistry HESI A2 Quizlet

1. Which elements are typically involved in hydrogen bonding?

A. Carbon, hydrogen, oxygen
B. Fluorine, chlorine, oxygen
C. Fluorine, chlorine, nitrogen
D. Fluorine, oxygen, nitrogen

Correct answer: D

Rationale: Hydrogen bonding occurs between hydrogen and highly electronegative atoms such as fluorine, oxygen, and nitrogen. These atoms have a strong pull on the shared electrons, leading to a partial negative charge on them, which allows them to form hydrogen bonds with hydrogen or other electronegative atoms. Choice A is incorrect because carbon is not typically involved in hydrogen bonding. Choice B is incorrect because chlorine is not as electronegative as nitrogen, and choice C is incorrect because nitrogen is more electronegative than chlorine.

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

A. 1
B. 2
C. 3
D. 4

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.

3. 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.

4. What charge do Group IIA elements typically have?

A. 1
B. +2
C. -3
D. 0

Correct answer: B

Rationale: Group IIA elements belong to the alkaline earth metals group in the periodic table. These elements typically have a charge of +2 because they readily lose two electrons to achieve a stable electron configuration. Therefore, the correct answer is B - +2. Choice A (1) is incorrect because Group IIA elements lose two electrons, not one. Choice C (-3) is incorrect because Group IIA elements do not gain electrons to have a negative charge. Choice D (0) is incorrect because Group IIA elements do lose electrons and have a positive charge, not a neutral charge.

5. What is the energy required to remove the outermost electron from an atom called?

A. covalent bonding
B. electronegativity
C. atomic radius
D. ionization energy

Correct answer: D

Rationale: Ionization energy is the energy needed to remove the outermost electron from an atom, resulting in the formation of a positively charged ion. The higher the ionization energy, the more difficult it is to extract an electron. Electronegativity, however, measures an atom's ability to attract shared electrons in a chemical bond. Atomic radius refers to the distance from the nucleus to the outermost electron. Covalent bonding involves sharing electron pairs between atoms to create a stable bond. Therefore, the correct answer is ionization energy as it specifically relates to the energy needed to remove an electron from an atom.