Concept explainers
Which of the following occurs when a covalent bond forms?
a. Electrons in valence shells are transferred from one atom to another.
b. Electrons in valence shells are shared between atoms.
c. Partial charges on polar molecules interact.
d. Nonpolar molecules are pushed together by surrounding water molecules.

Introduction:
Covalent bonds are formed by sharing of the electron pairs between atoms. These electron pairs are referred to as shared pairs or bonding pairs. The chemical bond in which the complete transfer of electron present in the outer shell takes place is known as an ionic bond.
Answer to Problem 1TYK
Correct answer:
Electrons in valence shells are shared between atoms.
Explanation of Solution
Explanation/Justification for the correct answer:
Option (b) is given that the bond is formed by the electron sharing. Covalent bonding occurs when pairs of electrons are shared between atoms. Atoms are covalently bond with other atoms by forming a full electron shell providing more stability. By sharing their outer most (valence) electrons, atoms can fill up their outer electron shell and gain stability. Hence, option (b) is correct.
Explanation for incorrect answers:
Option (a) is given that the valence shells are transferred. The chemical bond, in which the complete transfer of electron present in the outer shell occurs is known as an ionic bond. So, it is incorrect answer.
Option (c) The polar molecules have partial charges present on them, the interaction of the two-partial charged atoms results in the formation of the dipole-dipole interaction. It takes place when two molecules carry opposite partial charge. So, it is incorrect answer.
Option (d) The interaction between the water and the non-polar molecule, in which the non-polar molecules attract themselves is known as hydrophobic interaction. These molecules do not form bonding with the water molecules, as a result, they are forced to interact among themselves. So, it is incorrect answer.
Hence, options (a), (c) and (d) are incorrect.
Covalent bonds are formed when electrons are shared between atoms.
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Chapter 2 Solutions
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