Bell Work: Predict its reactivity! Draw an atom of sodium. Complete the following on today’s notes. Draw an atom of sodium. Write down how many valence electrons it has. (Ve- = _____) Predict its reactivity! Do you think it will gain or lose electrons? How many? Why?

Ve- = 1 Sodium is very reactive. It only has one valence electron so it will lose it very easily. It will bond with the Halogens, who need only one more electron to be full.

Preparing for TCAP… SPI 0807.9.1: In an atom, the _____________ has a negative charge. electron SPI 0807.9.3: Which of the following consists of elements only? A. Na, CO, H2O B. He, CO, Br C. Co, K, Cl D. Co, HCl, Ne

Preparing for TCAP… SPI 0807.9.9: On the periodic table, the group of elements that are known as the most reactive nonmetals are the ______________. halogens Today’s Objective: Understand that atoms can gain or lose electrons, which changes the atom’s overall charge. We call this an ion. Ions form ionic bonds.

Remember: Atoms are usually neutral. What does that mean? It means that the number of protons equals the number of electrons. So…if an atom has 42 protons, it will also have 42 electrons. There is an exception! Sometimes the atom will gain or lose electrons.

What is an ion? Ion—an atom that loses or gains an electron Positive ion—atom loses an electron Negative ion—atom gains an electron

Determining a Charge To determine an atom’s charge, you must compare the number of protons with the number of electrons. EXAMPLE: Sodium has an atomic # of 11. Sodium should have 11 electrons. On this model, Sodium only has 10 e-. So…this is a model of a Sodium ion. It’s Sodium 1+ ion. (11p – 10e = 1)

AROUND THE ROOM! There are atoms tapes around the room. With a partner, move around the room and decide if each atom is a NEUTRAL ATOM or an ION. Number 1-7 on the side of your notes. Write ATOM or ION for each one. Sit down when you are finished.

AROUND THE ROOM (Answers) #1 Atom

AROUND THE ROOM (Answers) #2 Atom

AROUND THE ROOM (Answers) #3 Ion

AROUND THE ROOM (Answers) #4 Ion

AROUND THE ROOM (Answers) #5 Atom

AROUND THE ROOM (Answers) #6 Ion

AROUND THE ROOM (Answers) #7 Atom

Making Predictions… Metals usually lose electrons. It is easier to LOSE one electron than it is to gain seven. (Remember: You need 8!) It is easier to GAIN two electrons than it is to lose six.

Let’s Practice… Will the following lose or gain electrons? LOSE GAIN

Sum it up… neutral Atoms usually have a __________ charge. ions Atoms with charges are called ________. ions If an atom has more electrons than protons, the atom will have a __________ charge. negative Metals _________ usually lose electrons.

Is this a neutral atom or ion?

Is this a neutral atom or ion?

Is this a neutral atom or ion?

What are ionic bonds made of? IONS An ion is a CHARGED atom. If an atom loses an electron, the atom becomes a POSITIVE ion.

Make the following table… Ionic Bond Covalent Bond Metallic Bond

Make the following table… Ionic Bond Covalent Bond Metallic Bond Electrons are transferred. Metal bonds to a nonmetal. Valence electrons of both elements have to add up to 8.

Predict the following ionic bonds: Read the following pairs of elements then decide if those elements would form an ionic bond. Predict the following ionic bonds: Sodium and Potassium Potassium and Fluorine Fluorine and Chlorine Sodium and Neon NO YES NO NO

Assignment: Ionic Bond Drawings Step 1: Divide your paper into 6 squares. Step 2: Draw the 2 atoms for each square below then use arrows to show the electrons being lost. Step 3: Under each drawing, indicate if it became positive or negative. (You should have two per box.) Sodium and Chlorine