Chapter 6 review from packet

If a bond's character is more than 50% ionic if the electronegativity difference between the two atoms is greater than _____

1.7

Arrange the following types of attractions in order of increasing strength, with 1 being the weakest and 4 the strongest ___ hydrogen bonding ___ ionic ___ dipole- dipole ___ London dispersion

3 4 2 1

Describe how a covalent bond holds two atoms together

A pair of electrons is attracted to both nuclei of the two atoms bonded together

Use the concept of potential energy to describe how a covalent bond forms between two atoms

As the atoms involved in the formation of a covalent bond approach each other, the electron-proton attraction is stronger than the electron-electron and proton-proton repulsions. The atoms are drawn to each other and their potential energy decreases. eventually, a distance is reached at which the repulsions between the like charges equals the attraction of the opposite charges. At this point, potential energy is at a minimum and a stable molecule forms

Name two elements that from compounds that can be exceptions to the octet rule.

Hydrogen and boron, beryllium, phosphorus, sulfur, and xenon

Use the concept of electron configurations to explain why the number of valence electrons in metals tends to be less than the number in most nonmetals.

Most metals have their outer electrons in s orbitals, while nonmetals have their outer electrons in p orbitals

Identify the major assumption of the VSEPR theory, which is used to predict the shape of atoms.

Pairs of valence electrons repel on another

What is the relationship between the enthalpy of vaporization of a metal and the strength of the bonds that holds them together?

The amount of energy required to vaporize a metal is a measure of the strength of the bonds that hold the metal together. The greater a metal's enthalpy of vaporization, the stronger the metallic bond.

What types of bonds are present in an ionic compound that contains a polyatomic ion?

The atoms in a polyatomic ion are held together with covalent bonds, but polyatomic ions combine with ions of opposite charge to form ionic compounds

How can electronegativity be used to distinguish between an ionic bond and a covalent bond?

The difference between the electronegativity of the two atoms in a bond will determine whether the bond is ionic or covalent. If the difference in electronegativity is greater than 1.7, the bond is considered ionic

Describe te electron distribution in a polar- covalent bond and its effect on the partial charges of the compound

The electron density is greater around the more electronegative atom, giving that part f the compound a partial negative charge. The other part of the compound has an equal partial positive charge

In water, two hydrogen atoms are bonded to one oxygen atom. Why isn't water a linear molecule?

The electron pairs that are not involved in bonding also take up space, creating a tetrahedron of electron pairs and making the water molecule angular or bent

How does the behavior of electrons in metals contribute to the metal's ability to conduct electricity and heat?

The mobility of electrons in network of metal atoms contributes to the metals ability to conduct electricity and heat

What orbitals combine to form sp3 hybrid orbitals around a carbon atom?

The s orbital and all three p orbitals form the second energy level

How are dipole- dipole attractions, London dispersion forces, and hydrogen bonding similar?

They are all forces of attraction between molecules. In all cases there is an attraction between the slightly negatively- charged portion of one molecule and the slightly positively charged portion of another molecule

What property of the two atoms in a covalent bond determines whether or not the bond will be polar?

electronegativity

What two factors determine whether or not a molecule is polar?

electronegativity difference and molecular geometry or unshared electron pairs

Write the formula for an example of each of the following compounds: _________________________ a. non polar covalent compound _________________________ b. polar covalent compound _________________________ c. ionic compound

h2 HCl NaCl

A chemical bond that results from the electrostatic attraction between positive and negative ions is called a(n) ________________________

ionic bond

What type of energy best represents the strength of an ionic bond?

lattice energy

If electrons involved in bonding spend most of the time closer to one atom rather than the other, the bond is ______________________

polar covalent

explain why resonance structures are used instead of lewis structures to correctly model certain molecules

resonance structure show that one lewis stricture cannot correctly represent the location of electrons in a bond. resonance structures show delocalized electrons, while lewis structures depict electrons in a definite location.

describe the force that holds two ions together in an ionic bond.

the force of attraction between unlike charges holds a negative ion and a positive ion together in an ionic bond

The electrons involved in the formation of a chemical bond are called _________________________

valence electrons