The Periodic Table Essential question: What is a Lewis Dot Structure and how do I find it?

Make appointments!

So how do we find it? First, in your notes draw the Bohr model for sodium Find your Fall appointment and help one another. Look at the Periodic Table. Do you see a trend?

Let's try it again!! Draw the Bohr model for Calcium Find your Winter appointment and help one another. Look at the Periodic Table. Do you see a trend?

Discussion Valence electrons Rule of octet

What is a Lewis Dot structure? Shows the number of valence electrons that an element has.

How do we draw it? First, write the symbol for the element Then, Add the number of valence electrons For example, Carbon has 4 valence electrons. It can be drawn as

You try Draw the Lewis Dot Structure for Sodium Barium Boron Krypton

Warm Up 1. Name an element that is in the same period as iron. 2. Circle the non-metal a. Gallium b. Barium c. Sulfur d. Mercury 3. How many protons and electron are there in Mg

What is an oxidation number? This is the charge of an ion

What are Ions? These are atoms with a negative or positive charge

Remember! Atoms are usually neutral because the number of protons equal the number of electrons. A=P=E

Stop and Think?! How would sodium obtain 8 valence electrons?

What is a Cation? These are positively charged atoms

What is a Cation? They lose electrons (donate) For example: Metals donate electrons!

For example How many electrons does the sodium ion have?

What is an Anion? These are negatively charged atoms

What is an Anion? They gain electrons(steal) Non-Metals gain electrons!

For example How many electrons does the chlorine ion have?

Periodic Trends OBJECTIVES: Describe periodic trends for first ionization energy, ionic size, and electronegativity.

Warm Up 1. Calculate the number of electrons in Zn Is Zn +2 a Cation or an Anion? 3. What is the oxidation number (charge) for the following? a) Ga b) F c) Fr

Atomic Radius- the size of the atom Increases as you go down a group and from right to left across a period.

Ionic Radius- the size of an atom when it forms an ion

Ionization Energy- the energy required to remove an electron Increases as you go up a group and as you go from left to right across a period

Electronegativity- the tendency of an atom to attract electrons Increases as you go up a group and across a period from left to right Electronegativity

Warm Up 1. How does Atomic Radius change from left to right across a period? 2. Which of the following has the smallest atomic radius? a. Carbon b. Nitrogen c. Silicon d. Phosphorus