Chemistry Chapter 8: Covalent Bonding Flashcards

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Questions and Answers

What is a covalent bond?

A bond formed by the transfer of electrons

A bond formed by sharing electrons (correct)

A bond formed by a metal and a nonmetal

A bond formed by ionic interactions

What is a molecule?

A neutral group of atoms joined together by covalent bonds.

What is a diatomic molecule?

A molecule that contains two atoms.

What is a molecular compound?

A compound composed of different elements that are made of molecules. Signup and view all the answers

What is a molecular formula?

The chemical formula of a molecular compound. Signup and view all the answers

What information does a molecular formula provide?

It shows how many atoms of each element a substance contains. Signup and view all the answers

What is the molecular formula of water?

H2O Signup and view all the answers

Molecular formulas describe molecules consisting of atoms of one element.

False Signup and view all the answers

What is the arrangement of the atoms within a molecule called?

A molecular structure. Signup and view all the answers

What is a single covalent bond?

Two atoms held together by sharing one pair of electrons. Signup and view all the answers

What is the result of electron sharing in covalent bonds?

Atoms attain the electron configuration of noble gases. Signup and view all the answers

How many bonds does carbon usually form?

4 Signup and view all the answers

What are the seven diatomic elements?

Fluorine, Chlorine, Bromine, Iodine, Hydrogen, Nitrogen, Oxygen. Signup and view all the answers

What is a double covalent bond?

A bond that involves two shared pairs of electrons. Signup and view all the answers

What is a triple covalent bond?

A bond that involves three shared pairs of electrons. Signup and view all the answers

What is a coordinate covalent bond?

A covalent bond in which one atom contributes both bonding electrons. Signup and view all the answers

Compounds containing polyatomic ions include ionic and covalent bonding.

True Signup and view all the answers

What are some exceptions to the octet rule?

Molecules with an odd number of valence electrons or less/more than a complete octet. Signup and view all the answers

What is bond dissociation energy?

The energy required to break the bond between two covalently bonded atoms. Signup and view all the answers

What is a polar bond?

A covalent bond between atoms where electrons are shared unequally. Signup and view all the answers

What is a polar molecule?

A molecule where one end is slightly positive and the other is slightly negative. Signup and view all the answers

What are hydrogen bonds?

Attractive forces where hydrogen covalently bonded to an electronegative atom is weakly bonded to another atom. Signup and view all the answers

The melting points of covalent bonds are high compared to ionic compounds.

False Signup and view all the answers

What are network solids?

Very stable substances that do not melt until 1,000 degrees or higher. Signup and view all the answers

Study Notes

Covalent Bonding Overview

Covalent bonds are formed when atoms share electrons, leading to stable molecular structures.
A molecule is defined as a neutral group of atoms bonded covalently.

Molecules & Molecular Compounds

Diatomic molecules consist of two atoms, while molecular compounds are formed from different elements held together by covalent bonds, such as water.
Molecular formulas represent the number of each type of atom in a molecule; for example, the molecular formula of water is H₂O.

Bond Types and Characteristics

Single covalent bonds involve sharing one pair of electrons; double and triple bonds involve two or three pairs, respectively.
Coordinate covalent bonds occur when one atom provides both electrons for the bond, represented with arrows.
Characteristics of molecular compounds include lower melting and boiling points compared to ionic compounds and a tendency to exist as gases or liquids at room temperature.

Electron Configuration

Atoms in covalent bonds aim for noble gas electron configurations through electron sharing, often forming double or triple bonds.
Carbon typically forms four covalent bonds, while halogens form single bonds in diatomic molecules.

Structural Representations

Structural formulas use dashes to represent covalent bonds and illustrate the arrangement of atoms.
Resonance structures depict molecules that can be represented by two or more valid dot structures with equivalent electron arrangements.

Molecular Geometry

VSEPR theory explains molecular shapes based on the repulsion between electron pairs.
The tetrahedral angle of molecular geometry is approximately 109.5 degrees.

Polar and Nonpolar Bonds

Covalent bonds may be nonpolar (equal sharing of electrons, e.g., diatomic elements) or polar (unequal sharing, leading to partial charges).
The distribution of charges in polar bonds is determined by the differences in electronegativity between atoms.

Intermolecular Forces

Intermolecular attractions are weaker than ionic or covalent bonds but influence the states of matter—solid, liquid, or gas.
Van der Waals forces include dipole interactions (attractions between polar molecules) and dispersion forces (weak attractions between nonpolar molecules).
Hydrogen bonds are specific interactions where hydrogen attached to electronegative atoms (like O, N, or F) is attracted to unshared electron pairs from other electronegative atoms.

Physical Properties of Covalent Compounds

Covalent compounds often have low melting and boiling points due to weak intermolecular forces.
Network solids are an exception, being strong, stable substances that require high temperatures (above 1000 degrees) to melt due to extensive covalent bonding throughout the structure.

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Description

Test your knowledge of covalent bonding with these flashcards from Chemistry Chapter 8. Each card includes key definitions and concepts related to covalent bonds, molecules, and molecular compounds. Perfect for students looking to reinforce their understanding of chemistry.