Chemical Bonds

Positively charged ion

Cations

Name the family of elements that make 1- anions.

Halogens (Group 17)

Energy required to change solid metal into a gas

Heat of Vaporization

Melting/Boiling points of Ionic Compounds are very ____.

High

Electrostatic attraction between ions

Ionic bond

What does triatomic mean?

It has 3 atoms.

Shows valence electrons as dots

Lewis Dot Structures

When atoms bond, what are they trying to achieve, in terms of ENERGY?

Lowest potential energy

Metal atoms bonded to several other atoms

Metallic bond

Compare the Lewis strutures for polar covalent compounds and nonpolar covalent compounds.

Polar covalent compounds have unequal electron sharing, while Nonpolar have equal electron sharing.

Atoms share one pair of electrons

Single Covalent Bond

What relationship exists between an atom's valence electrons and the number of dots in the Lewis structure of the atom?

The dots represent the valence electrons of that element.

Why are most molecular compounds gases at room temperature?

The forces of attraction between individual molecules are not strong.

Which bonds are the shortest: single, double, or triple?

Triple

What are the 3 electrostatic interactions in covalent bonds?

~Attractions between electrons and nuclei ~Repulsions between electrons ~Repulsions between nuclei

When determining the number of electron domains in a Lewis structure, what do you count?

~Bonds on the center atoms ~Lone pairs on the center atom

What does a solid line between two element symbols represent in the drawings of the molecules?

2 shared electrons (bonds)

For nonmetal ions, generally the number of electrons shown is __ since enough electrons are transferred to the previously partially filled _______ shell of the nonmetal atom in order to form the ion.

8; Valence

Name the family of elements that make 2+ cations.

Alkaline Earth Metals (Group 2)

Negatively charged ion

Anion

In general, do nonmetals form anions or cations?

Anions

What does the word "domain" mean?

Area/Region

What relationship exists between bond length and bond energy?

As bond length decreases, bond energy increases.

What is the relationship that would be logical between the bond length and bond energy of a single bond compared to a double bond compared to a triple bond?

As the number of bonds and bond energy increases, bond length decreases.

The energy needed to break covalent bonds

Bond energy

Explain the difference between a bonding electron domain and a nonbonding electron domain.

Bonding electron domains are areas around the central element made of shared electrons. Nonbonding are areas around the central atom where electrons aren't shared.

How do ionic compounds get to minimum potential energy?

By combining in a crystal lattice

How are negative ions formed?

By gaining electrons

How are positive ions formed?

By losing electrons

In general, do metals form anions or cations?

Cations

Shows the relativd numbers of atoms of each element in a compound using symbols and subscripts (ionic or covalent)

Chemical Formula (NaCl, BaSO₄, H₂O, C₁₂H₂₂O₁₁)

Sharing of electrons

Covalent bond

Chemical bonds that share electrons

Covalent bonds

Most Ionic Compounds are ________ _______ at room temperature.

Crystalline Solids

Lattice energy _________ down a group.

Decreases

Valence electrons actually ________...they are _______.

Delocalize; mobile

A molecule that contains 2 of the same atoms (more stable together than apart)

Diatomic Molecule

__________ in electronegativity reflect the character of bonding between the elements.

Differences

The attractive forces _________ until the outer shells overlap and form a "bonding orbital".

Dominate

Atoms share two pairs of electrons

Double Covalent Bond

Which subatomic particle carries a negative charge?

Electron

The tendancy an atom has to attract electrons

Electronegativity

There are several ___________ ____________ in covalent bonds.

Electrostatic interactions

Two bonds on the same atom will try to get as ____ ____ each other as possible.

Far from

The metal atoms have ____ valence electrons and many ______ orbitals.

Few; Vacant

When atoms form ions, the usually _____ or ____ enough electrons to achieve the electron _____________ of a noble gas.

Gain; Lose; Configuration

Lewis structures are easier to draw than Bohr diagrams, but what information is lost by drawing a Lewis structure instead of a Bohr diagram?

How many electrons are in the other energy levels/ How many energy levels it has

Square brackets are used to emphasize the fact that the structure is an _____, not an atom.

Ion

In general, how do ionic and molecular compounds compare in terms of melting points, boiling points, and ease of vaporization?

Ionic has higher melting points, boiling points, and easily vaporizes compared to molecular compounds.

Ionic Compounds split into _____ when molten or dissolved in water.

Ions

In a dot diagram the symbol for the element represents the _______ of the ion.

Kernel

Forming a crystal lattice minimizes a compound's ________ Energy.

Lattice

Energy released when one mole of an ionic crystalline structure is formed from gaseous ions

Lattice Energy

How are bond strengths determined for ionic compounds?

Lattice Energy

In general, double bonds are ________ than triple bonds.

Longer

Metal atoms ____ electrons; nonmetal atoms ___ electrons.

Lose; Gain

Depends on the nuclear charge and number of electrons in the sea of electrons

Metallic Bond Strength

The chemical bond that results from the attraction between metal atoms and the surrounding sea of electrons

Metallic Bonding

Shows the types and numbers of atoms combining in a molecular compound (specifically covalent)

Molecular Formula (H₂O, C₁₂H₂₂O₁₁)

What is the difference between positive and negative lattice energies?

Negative releases energy, while Positive gains energy.

Covalently bonded atoms in a continuous network extending throughout the material

Network Solid/ Covalent Solid/ Covalent Crystals

Is a charged indicated on the neutral atom?

No

Could a +3 ion of aluminum be made by adding three protons to an aluminum atom? Explain.

No because adding protons would change the entire element.

A covalently bonded compoun which has an equal distribution of electrons

Nonpolar Molecule

Which bonds are symmetrical?

Nonpolar bonds

Propose a mathematical equation to calculate the charge on an ion from the number of protons and electrons in an ion.

Number of protons - Number of electrons

Atoms in compounds tend to have a noble gas configuration

Octet Rule

How many covalent bonds will oxygen, hydrogen, nitrogen, and carbon form?

Oxygen: 2 Hydrogen: 1 Nitrogen: 3 Carbon: 4

The greater the difference in electronegativity, the more ________ the bond is.

Polar

A covalently bonded compound which has an unequal distribution of electrons

Polar Molecule

Which bonds are asymmetrical?

Polar bonds

Polarity affects the ________ of the shared electrons.

Position

Which subatomic particle carries a positive charge?

Proton

A lone pair of electrons and a bonded pair of electrons will ____ _______ from each other.

Push away

Pairs of electrons will ______ each other.

Repel

Metals can be thought of as cations suspended in a "____" of valence electrons.

Sea

In covalent bonds, atoms _____ electrons.

Share

In general, the stronger the bonds, the ________ the bonds.

Shorter

If elements are in the same column of the periodic table, they must have Lewis Structures that are ________.

Similar

Lattice energy measures how ________ the compound is.

Strong

Explain why a formula without electronegativity data or a Lewis structure cannot be used to predict bond type.

The bond type depends upon the difference in the electronegativities, so without knowing the electronegativity or the number of valence electrons, bond type cannot be predicted.

Compare the strengths of ionic and covalently bonded compounds.

The forces between molecules of a covalent bond are much weaker than that of an ionic bond.

What does bond length tell us about the strength of the covalent bond?

The longer the length, the weaker the bond.

What distinguishes a neutral atom from an ion?

The number of electrons

Why does sodium have the same Lewis structure as lithium?

They exist in the same column.

Where is the ion charge located in the isotope symbol?

Top right

Where in the periodic table are the elements whose atoms make more than one type of ion usually found?

Transition Elements (Middle)

Atoms share three pairs of electrons

Triple Covalent Bond

In general, which kind of bond would be harder to break: single, double, or triple?

Triple because the majority of the element's electrons are being shared by one another.

Why does nitrogen's Lewis Structure have five dots around it while nitrogen's Bohr diagram contains 7 dots around it?

Two of the 7 are not valence electrons.

When 2 electronegativites are moderately different, the shared electrons will be shared _________.

Unevenly

What does a pair of dots represent in the drawing of the molecules?

Unsharedd valence electrons

For positive ions, generally no electrons are indicated since all the _______ electrons have been transformed.

Valence

Electrons in the outermost shell of the atom

Valence electrons

Bonds with a low bond energy are ______ than bonds with a high bond energy.

Weaker

For transition elements, is it necessary to memorize the type of ion each element makes or could you predict the ion charge using a periodic table?

You could predict the ion charge using a periodic table, because elements of the same family have the same ion charge.

What are 4 properties of metals?

~Good conductors of heat/electricity ~Malleable ~Ductile ~Luster

What are the 3 basic types of bonds?

~Ionic ~Covalent ~Metallic

What are the 3 intramolecular forces?

~Ionic ~Covalent ~Metallic

What are the 5 properties of Network Solids?

~No individual molecules ~Very hard ~Very high melting points ~Poor conductors of heat and electricity ~Make good insulators/abrasives