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

2. Preparing for TCAP…
SPI : 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.

3. 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.

4. 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

6. 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)

7. 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.

8. AROUND THE ROOM (Answers)#1
Atom

9. AROUND THE ROOM (Answers)#2
Atom

10. AROUND THE ROOM (Answers)#3
Ion

11. AROUND THE ROOM (Answers)#4
Ion

12. AROUND THE ROOM (Answers)#5
Atom

13. AROUND THE ROOM (Answers)#6
Ion

14. AROUND THE ROOM (Answers)#7
Atom

15. 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.

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

17. 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.

18. Is this a neutral atom or ion?

19. Is this a neutral atom or ion?

20. Is this a neutral atom or ion?

21. 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.

22. Make the following table…
Ionic Bond Covalent Bond Metallic Bond

23. 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.

24. 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

26. 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