Opposites Attract Properties of Ionic Compounds

Poll

What science class would you like to take next year?

• AP physics

• AP Chemistry

• College Physics

• Honors Physics

• Something else

Unit 7 Assessment: Ionic Bond Review and Analogies

• A nonmetal atom takes electrons from a metal atom to become negative

• The negative and positive charges attract, holding the atoms together

• The overall charge of an ionic compound is always ZERO

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Ionic bonds Review

• All atoms want to have 8 valence electrons

• Atoms with fewer than 4 valence electrons tend to LOSE them

• Atoms with greater than 4 valence electrons tend to GAIN them

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​The Octet Rule

The nonmetal takes electrons because it has nearly a full octet and HIGH electronegativity.

The metal gives electrons because it has few valence electrons and LOW electronegativity.

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Why are electrons transferred in an ionic bond?

The charge of an ion is determined by the number of valence electrons/group number:
1A = 1 ve- = +1 7A= 7 ve- = -1
2A = 2 ve- = +2 6A = 6 ve- = -2
3A = 3 ve- = +3 5A = 5 ve- = -3

Charges of ions

Ionic compounds are usually soluble in water, and they conduct electricity when dissolved. Ionic solids are usually brittle (crushed easily).

Properties of Ionic Compounds

Other things to know about ionic bonds/compounds

Instructions

​1. Answer the following questions about ionic bonds
2. Create an analogy for ionic bonds
(make sure to identify the electrons, the metal cation, and the nonmetal anion!)

Multiple Choice

An ionic bond forms between a ______ and a _________.

• metal, metal

• metal, nonmetal

• nonmetal, nonmetal

• atom, ion

Fill in the Blank

Atoms form ions and bonds so that they can have 8 valence electrons. This is known as the _____ rule.

The opaque, white, brittle solid in the image has the chemical formula, NaF.

Multiple Choice

The name of this compound is

• sodide fluoride

• sodide fluorine

• sodium fluorine

• sodium fluoride

NaF is commonly found in toothpaste and drinking water as an additive to prevent tooth decay. Fluorine is an important element in tooth enamel, the tough tissue that protects your teeth.

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Multiple Choice

In NaF, F is the ______ and Na is the ______

• cation, anion

• metal, cation

• anion, cation

• womanion, manion

Multiple Choice

In NaF, how many electrons are transferred from Na to F?

• 7

• 9

• 1

• -1

Multiple Select

Which of the ions below are polyatomic ions?

• Na+

• H+

• OH-

• CN-

Open Ended

NaF is soluble in water. What happens to the atoms in NaF when it begins to dissolve in water?

(In the image, the red and white molecules represent water. The green atoms are F-, and the white atoms are Na+)

Analogy example

"An ionic bond is like an unhealthy relationship, where one person always takes and the other person always gives. The person who gives represents the metal cation with low electronegativity, which always gives electrons. The person who always takes is the nonmetal anion with high electronegativity, which always takes electrons. The electrons are represented by the things being given and taken in the relationship."


Please do your best to make your analogy unique!

Open Ended

What are you comparing to an ionic bond in your analogy? (What is the subject of your analogy?)

Open Ended

What represents your nonmetal anion in your analogy? Please explain.

Open Ended

What represents your metal cation in your analogy? Please explain.

Open Ended

What represents the electron(s) in your analogy? Please explain.