Chapter 5 Test Review Flashcards
An atom or group of atoms that has a positive or negative electric charge because it has lost or gained electrons is a(n):
ion
In most chemical reactions, atoms tend to match the outer electron configurations of the noble gases. This is called the ___ rule.
octet
Many stable ions have an electron configuration of a :
noble gas
The arrangement of ion in sodium chloride shows that each ion is surrounded by __ oppositely charged ions.
six
The attractive force between sodium ions and chloride ions results in an arrangement of ions in repeating units arranged to form a:
crystal lattice
In the sodium chloride crystal arrangement, the net effect is that the ______ between oppositely charged ions is significantly greater than _______ between ions of like charge.
attraction, repulsion
The arrangement of cations and anions depends of the ____ and the ______ of the ions.
size, ratio
The specific way in which atoms are arranged in an ionic compound is called the:
crystal lattice
The _______ is the simplest repeating unit of a crystal structure.
unit cell
A ____ is a compound that results when an ionic bond is formed between a cation and an anion.
salt
When 1 mole of a salt is formed from gaseous ions, ___________ is released.
lattice energy
Describe why the structure of ionic compounds causes the compounds to be hard.
The bond structure is very strong, and as long as the ions remained lined up in the lattice, it is very difficult to break.
When a force is applied to an ionic compound and ions are repositioned so that like-charged ions are located next to each other, what happens to the compound?
The repulsive force between the layers will cause the layers to break apart.
How is an ionic bond formed?
Since opposite charges attract, cations and anions attract each other, and an ionic bond is formed.
Define salt.
A compound resulting from the formation of an ionic bond between a cation and an anion.
Why do ionic compounds have high melting points and high boiling points?
Because each ion has a strong bond to each neighboring ion and these bonds must be broken for melting and boiling to occur.
Why are ionic solids generally poor conductors of electricity?
The ions in ionic solids are not free to move around and conduct the current.
When are salts excellent conductors of electricity?
When they are liquid or in solution.
Name the five characteristics of ionic compounds.
Solid at room temperature, hard and brittle, do not conduct electricity in solid form, good conductors in a liquid state or when dissolved in water, high melting and boiling points
How do those five properties relate to the nature of ionic bonds?
Most of them are results of ionic bonds being extremely strong. It is hard to break the compound apart, but when the bonds are finally broken, the charged particles are good conductors of electricity.
Describe the structure of salt crystals.
Form repetitive geometric arrangements of ions, atoms, or molecules.
How do the outer shell electron configurations for ions of Group 1, Group 2, and Group 15, Group 16, and Group 17 elements compare with those of the noble gases?
Ions of group 1 and 2 have the electron configuration of the noble gas in the previous period. Groups 15,16,17 ions have the electron configuration of the noble gas following them on the periodic table.
What do you notice about all of the ionic charges for Group1? Group 2? Group 15? Group 16? Group 17?
Group 1: all +1
Group 2: all +2
Group 15: all -3
Group 16: all -2
Group 17: all -1
Explain why the properties of ions differ from those of their parent atoms.
Ions have different electron configurations than their parent atoms, they act more like atoms with their electron configuration than they do their parent atoms
Why do atoms of metals form cations?
The energy required to remove electrons to form cations with a noble gas configuration is less than the energy required to add electrons to form an anion.
Why do atoms of nonmetals form anions?
The energy required to add electrons so their ions have a noble gas electron configurations is less than the energy required to remove enough electrons.
Having equal amounts of positive and negative charges is called:
electroneutrality
Collections of _____ are never found without a similar number of anions nearby to effectively neutralize the charges.
cations
When an element forms two or more positive ions, the ions are distinguished by using ______ to indicate the charge
roman numerals
How do the formulas for atomic salts relate to their names?
It gives the number of cations and anions present.
What are the endings of polyatomic ions containing oxygen?
-ite and -ate
What “replaces an oxygen by a sulfur” in the anion?
thio-
What is a regular, infinitely repeatable pattern in which a crystal is arranged?
crystal lattice
What is the smallest portion of a crystal lattice that shows the 3 dimensional structure of the entire lattice?
unit cell
Define lattice energy.
The amount of energy needed to break crystal lattice up into separate ions.
What are ionic compounds that include water in their crystal structure?
hydrates
What factors affect lattice energy?
charge and radius/ size
What does isoelectronic mean?
having the same number electrons
What is a polyatomic ion composed of an element, usually a nonmetal, bonded to one or more oxygen atoms
oxyanion
What proposes that all metal atoms in a metallic solid contribute their valence electrons to form a “sea” of electrons, and can explain properties of metallic solids such as malleability, conduction, and ductility?
The electron sea model
What electrons are involved in metallic bonding that are free to move easily from one atom to the next throughout the metal and are not attached to a particular atom?
delocalized electrons
What is the attraction of a metallic cation for delocalized electrons
metallic bond
Define alloy.
A mixture of elements that has metallic properties
