study guide Section 2 Ionic bonds and Ionic compounds & answers

1. Name:……………………………………………
Grade: ……………10………………………..
Subject:Chemistry
:Date ………………………
Chapter 7 : Ionic compounds and Metals
Section 2 : Ionic bonds and Ionic compounds
1- Oppositely charged ions attract each other, forming
electrically neutral ionic compounds
Formation of an Ionic Bond
2- The electrostatic force that holds oppositely charged particles
together in an ionic compound is referred to as an ionic bond.
3- Compounds that contain ionic bonds are ionic compounds If
ionic bonds occur between metals and the nonmetal (oxygen) ,
oxides form. Most other ionic compounds are called salts.
Binary ionic compounds
4- Thousands of compounds contain ionic bonds. Many ionic
compounds are binary, which means that they contain only two
different elements
5- Sodium chloride (NaCl) is a binary compound because it
contains two different elements, which are sodium and
chlorine.

2. Compound formation and charge
Example: (calcium fluoride )
6- Calcium has the electron configuration [Ar] 4s 2 , and needs to
lose two electrons to attain the stable configuration of argon.
Fluorine has the configuration [He]2 s 2 2p 5 , and must gain one
electron to attain the stable configuration of neon. Because the
number of electrons lost and gained must be equal, two fluorine
atoms are needed to accept the two electrons lost from the
calcium atom. he overall charge of one unit of calcium fluoride
(CaF2 ) is zero
7- formation of an ionic compound such as sodium chloride can
be represented

3. Properties of Ionic Compounds
8- the ionic bonds produce unique physical structures, unlike those
of other compounds
9- A crystal lattice is a three-dimensional geometric arrangement
of particles
In a crystal lattice, each positive ion is surrounded by negative
ions, and each negative ion is surrounded by positive ions.

4. Physical properties
10- Melting point, boiling point, and hardness are physical properties
of matter that depend on how strongly the particles that make up the
matter are attracted to one another
11- the ability of a material to conduct electricity—depends on the
availability of freely moving charged particles.
12-In the solid state, the ions in an ionic compound are locked into
fixed positions by strong attractive forces. As a result, ionic solids do
not conduct electricity.
13-when an ionic solid melts to become a liquid or is dissolved in
solution. The ions are now free to move and conduct an electric
current.
14-Both ionic compounds in solution and in the liquid state are
excellent conductors of electricity.
15- An ionic compound whose aqueous solution conducts an electric
current is called an electrolyte
16- Because ionic bonds are relatively strong, ionic crystals require a
large amount of energy to be broken apart Thus, ionic crystals have
high melting points and high boiling points,
17- Ionic crystals are also hard, rigid, brittle solids due to the strong
attractive forces that hold the ions in place.
18- When an external force is applied to the crystal a force is strong
enough to overcome the attractive forces holding the ions in position
within the crystal—the crystal cracks or breaks apart

5. 19- The crystal breaks apart because the applied force repositions the
like-charged ions next to each other; the resulting repulsive force
breaks apart the crystal.
Energy and the Ionic Bond
20- During every chemical reaction, energy is either absorbed or
released.
21- If energy is absorbed during a chemical reaction, the reaction is
endothermic. If energy is released, it is exothermic
22- The formation of ionic compounds from positive ions and
negative ions is always exothermic.
23- The greater the lattice energy, the stronger the force of attraction.
24- crystal lattice is a three-dimensional geometric arrangement (
shape ) of particles In a crystal lattice, each positive ion is
surrounded by negative
25- Lattice energy is directly related to the size of the ions bonded.
Because the electrostatic force of attraction between opposite charges
increases as the distance between the charges decreases,

6. 26- Smaller ions produce stronger interionic attractions and greater
lattice energies.
27 - The lattice energy of a lithium compound is greater than
that of a potassium compound containing the same anion because the
lithium ion is smaller than the potassium ion.
28 - The value of lattice energy is also affected by the charge of the
ion.
29 - The ionic bond formed from the attraction of ions with larger
positive or negative charges generally has a greater lattice energy.