1. Do-Now: There are a finite / infinite number of elements in the Universe. (circle one)

2. Bonding
SC.8.P.8.5: Recognize that there are a finite number of elements and that their atoms combine in a multitude of ways to produce compounds that make up all of the living and nonliving things that we encounter.

3. What is a chemical bond?
A chemical bond is an attraction between atoms that allows the formation of chemical substances that contain two or more atoms.
The bond is caused by the electrostatic force of attraction between opposite charges.
The strength of chemical bonds varies considerably; there are "strong bonds" such as covalent or ionic bonds and "weak bonds" such as dipole–dipole interactions, the London dispersion force and hydrogen bonding.

4. What is a chemical bond? Vocabulary:
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions.
A molecule is an electrically neutral group of two or more atoms held together by chemical bonds. Molecules are distinguished from ions by their lack of electrical charge.
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving the atom a net positive or negative electrical charge.

5. Molecule, Compound, or Both?
Nitrogen
Cl2
Chlorine
NO2
Nitrogen Dioxide
CO2
Carbon Dioxide O2
Oxygen
CH4
Methane H2
Hydrogen NO
Nitric Oxide
H2O
Water

6. What is a chemical bond?
Remember the octet rule!!! The octet rule is a chemical rule of thumb that states that atoms of low (<20) atomic number tend to combine in such a way that they each have eight electrons in their valence shells, giving them the same electronic configuration as a noble gas.

7. How is an ionic bond different from a covalent bond?
A covalent bond is a chemical bond that involves the sharing of electron pairs between two nonmetals. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding. For many molecules, the sharing of electrons allows each atom to attain the equivalent of a full outer shell, corresponding to a stable electronic configuration.

8. How is an ionic bond different from a covalent bond?
Example
# of atoms
Lewis Dot Structure
CH4
NH3
As2O5
PCl3
Draw Lewis Dot Structure (how many valence electrons are available?)
Share/donate electrons to obey octet rule.

9. How is an ionic bond different from a covalent bond?
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed due to the attraction between an atom that has lost one or more electron (known as a cation) and an atom that has gained one or more electrons (known as an anion). Usually, the cation is a metal atom and the anion is a nonmetal atom.

11. How is an ionic bond different from a covalent bond?
Example
# of atoms
Lewis Dot Structure
NaBr
KBr
NaCl
NaF
Draw Lewis Dot Structure (how many valence electrons are available?
Share/donate electrons to obey octet rule.

12. Word Wall: Ionic bond Covalent bond Valence Outer shell Compound
Ionic compound
Covalent compound
Molecule
Ion
Charge