Chemical Bonds: The force that holds two atoms together

Ionic Bonds: When positive protons are attracted to negative electrons

Ions Recap:

• the particles that make up atoms have either positive or negative charge

• they would cancel each other out (net gain of 0), and that’s an atom

Positive Particles: Protons

Negative Particles: Electrons

• Protons are located in the center and electrons are on the outside… only electrons can be taken away

  • When an electron is added, the net charge becomes negative (adding one negative charge)

  • When an electron is removed, the net charge becomes positive (removing a negative charge)

• An atom with positive or negative charge is called an ION

• Elements WITHOUT charge are called ATOMS

Ionic Bond:

Ionic bonds are formed between two ions by the TRANSFER of electrons

• Octet Rule Review:

  • In forming compounds, atoms tend to achieve the electron configuration of a noble gas… (valence electron of 8)

  • metal atoms tend to lose, gaining a complete octet in the next lowest energy level, while nonmetals tend to gain electrons to achieve a complete octet

CATIONS:

• positive ions (or “paw”sitive ions)

• an atom would lose their valence electrons

ANIONS:

• negative ions

• an atom gains valence electrons

• element name usually ends with -ide after it becomes an anion

  • Chlorine = Chloride

Ionic compounds consist of cations and anions

• usually composed of metals/non-metals

• the final compound is neutral (0)

Properties of Ionic Compounds:

1. most are crystalline solids at room temperature

2. have high melting points and high boiling points

3. very hard

4. ionic compounds can conduct and electric current when melted or dissolved in water because their ions are free to move (electrolytes)

Lewis Dot Diagrams:

When drawing lewis dot diagrams, we draw the valence electrons of each ion. they go around the element abbrivation

Chemical formulas are written based on the ratio of the elements. The cation always goes first, and then the anion. If there’s multiple of the element being used, we would use a subscript to indicate that amount

Naming Ionic Compounds

• Write the name of the cation (metal) first, then anion

  • calcium, for example, becomes calcium ion

• When writing the name of the anion, usually, we take the root and add -ide onto it

  • chlorine, for example, becomes chloride

• Together CaCl2 becomes Calcium Chloride