Ch. 6 Chemistry Study Guide

What's a covalent bond?

Bond created from the sharing of pairs of electrons between two atoms; each atom uses the shared e- as their own.

Define diatomic molecule?

Contains two atoms.

How is a double bond and a triple bond represented?

Double lines, triple lines.

Define electronegativity, and explain how electronegativity values are used to determine bond type.

Electronegativity is a measure of an atom's ability to attract electrons. Determines the bond between two atoms is ionic or covalent, you can calculate the difference in the two atoms electronegativities. 0. - 0.3 = non polar covalent 0.3 - 1.7 = polar covalent 1.7 or more = ionic

What is lattice energy and what are they used for?

Energy released when one mole of ionic crystalline compound is formed from gaseous ions. They're used to to compare bond strengths in ionic compounds.

What is bond energy?

Energy required to break a chemical bond and form neutral isolated atoms

What is a molecular formula?

Formula for a molecule that gives the number and type of atoms in one unit.

What is an octet of electrons?

Full valence levels (s & p); Chemical compounds form so each atom can have 8 electrons in their highest energy level.

How are the strength of metallic bonds measured?

Heat of vaporization.

What is bond length?

The average distance between two bonded atoms at their lowest energy.

Why do ionic compounds have higher melting and boiling points than molecular compounds?

The forces between the atoms pulling together.

What information is given in a chemical formula?

The relative numbers and types of atoms in a compound by using atomic symbols and numerical subscripts.

State the VSEPR theory?

The repulsion between the sets of valence level electrons surrounding an atom causes these sets to be oriented as far apart as possible.

How does the VSEPR theory predict the shapes of molecules?

The shapes are determined by the number of atoms and lone pairs.

What does the chemical formula for an ionic compound represent?

The simplest ratio of the compound's combined ions that gives electrically neutrality.

What is the correlation between bond length and bond strength?

The stronger the bond the shorter the length.

Explain electron dot notation, and how they are related to Lewis structures.

They're related by the dot diagrams to show the bond between atoms. Lewis = combination of dot diagrams.

What is the general rule for metals joining with nonmetals? Ionic bonds nonmetals with metals?

Two nonmetals usually form covalent bonds, and metals and nonmetals usually form ionic bonds.

What's an ionic bond?

Two oppositely charged ions are electrically attracted to each other; atoms completely give up electrons.

What is a polyatomic ion?

A charged ion of two or more covalently bonded atoms

What makes the noble gases "noble"?

All of their outer shells are full (s&p are the outer shells)

Why do atoms form chemical bonds?

Atoms bond to achieve a more stable valence electron arrangement; octet electrons.

How do most ionic compounds exist?

In Crystalline solids.

What does a structural formula indicate?

Indicates the kind, number, and arrangement of bonds, but not the unshared pairs of atoms in a molecule.

Explain what intermolecular forces are, and how they are different from the other forces that govern chemical bonding

Intermolecular forces are the attraction between molecules. They are generally weaker. The forces between molecules when the float around.

How are bond energies usually reported?

Kilojules per mole

What accounts for the "roaming" electrons in metallic bonding, and what properties of metals do they allow?

Metal atoms loosely hold on to their valence electrons.

What is a chemical bond?

Mutual electrical attraction between the nuclei and valence electrons of different atoms that bonds those atoms together.

What is a crystal lattice?

The 3D arrangement minimized of atoms inside a crystal.

What is a molecule?

Neutral group of atoms that are held together by covalent bonds and are capable of existing as a single unit own their own

What makes a bond polar or non polar?

Non polar = electrons are shared equally. Polar = unequal attraction and distrubution of electrical charges.

What is a lone pair, as it relates to electron dot notation.

Pair of unshared electrons that are not involved in bonding and they belong exclusively to one atom.

In Lewis structures, how are single-bonded electrons represented?

Produced by the sharing of one pair of electrons between two atoms. It is drawn as a single line between the atoms that are bonded.

What is a double bond?

Produced by the sharing of two pairs of electrons and are shown by two lines between the bonded atoms.

Explain the process of the formation of a covalent bond. Why does it happen?

Since atoms want to be at the lowest potential energy, the attraction between nuclei and electron clouds pull atoms closer. Repulsion keeps them apart. This "struggle" continues until a stable arrangement is formed.