1. Bonding and Chemical Compounds
Table of Contents
Atoms and Bonding
Elements Forming Compounds
Classifying Chemical Compounds

2. Atoms and Bonding Electron Dot Diagrams The valence electrons of
an atom are shown as dots around the symbol of the element. Complete the electron dot diagram for neon.
Remember, valence electrons are electrons that have the highest energy.
The number of valence electrons in each atom helps determine the chemical properties of that element.

3. Atoms and Bonding

4. Atoms and Bonding
The symbols for the elements in Periods 2 and 3 are shown below. Complete the electron dot diagrams for nitrogen, oxygen, fluorine, sodium, magnesium, aluminum, silicon, and argon.

5. Atoms and Bonding
Metal atoms react by losing their valence electrons. The reactivity of metals decreases from left to right.
Nonmetals become stable when they gain (usually combining with metals) or share (usually with other nonmetals or metalloids) electrons.
Metalloids can lose or share electrons.
Hydrogen shares its electrons with other nonmetals.

6. Elements Forming Compounds
How Ions Form
When a neutral atom transfers one or more electron to another atom, it results in the formation of an ionic compound.
An atom that loses one of its electrons becomes a positively charged ion. The atom that gains the electron becomes a negatively charged ion.

7. Elements Forming Compounds
Formation of an Ionic Bond
Follow the steps to see how an ionic bond forms between a sodium atom and a chlorine atom. Complete the electron dot diagrams.

8. Elements Forming Compounds
Chemical Formulas
What chemical symbols are present in this formula. Where and what is the subscript?
Athletic Chalk
Athletes use chalk to lubricate their hands and dry up sweat. The white powdery chalk is actually an ionic compound called magnesium carbonate. Identify the carbonate ion in the chalk's formula shown below. What is the charge of each ion?

9. Elements Forming Compounds
Use the periodic table to complete the table.

10. Elements Forming Compounds
Covalent Bonds
Atoms can form single, double, and triple covalent bonds by sharing one or more pairs of electrons. Covalent bonds between the shared electrons of each atom hold the atoms together to form a molecular compound.

11. Elements Forming Compounds
Nonpolar and Polar Bonds
Hydrogen forms a nonpolar bond with another hydrogen atom. In hydrogen fluoride, fluorine attracts electrons more strongly than hydrogen does. The bond formed is polar.

12. Elements Forming Compounds
Nonpolar and Polar Molecules
Both carbon dioxide and water molecules contain polar bonds. Where would + and - signs be placed to show positive and negative charges?

13. Elements Forming Compounds
Metallic Bonding
The positively charged metal ions are embedded in a “sea” of valence electrons.
Each property of metals is determined by the structure of metal atoms and the bonding between their valence electrons.
When metal atoms combine with atoms of other elements they usually lose electrons

14. Classifying Chemical Compounds
In general, ionic compounds form hard crystals with high melting points and conduct electric current when dissolved in water or melted.
Molecular compounds usually do not conduct electric current when melted or dissolved in water and usually have lower melting points.

15. Classifying Chemical Compounds
The table shows the melting points and boiling points of a few molecular and ionic compounds. Circle the ionic compounds, underline the molecular compounds.

16. Classifying Chemical Compounds
Acid and Base Properties
An acid reacts with metals and carbonates, tastes sour, and turns blue litmus paper red.
A base tastes bitter, feels slippery, and turns red litmus paper blue.
Which items are acids and which are bases?
Window
cleaner
Limes
Dish soap
Vinegar

17. Classifying Chemical Compounds
Salts
What happens when you mix an acid and a base?
A reaction called neutralization and results in the formation of a salt.
A salt is any ionic compound that can be made from a neutralization reaction.
Salts are made of the positive ion of a base and the negative ion of a acid.
Since salts are made from ions, they share the same properties of ionic compounds, including crystal shape, high melting points and boiling points, and electric conductivity.

18. Classifying Chemical Compounds
Bonding determines the properties of a compound
Using water and sodium chloride as examples, complete the sentences about compounds.

19. Classifying Chemical Compounds
pH Scale
Acidic Basic