Good Morning! April 21, 2023

• Starter: What is an ion?

• Today we will be exploring the wonderful world of Ions!

• We will be learning the charges of common ions

• Their names and what you call them when they bond.

Why do atoms become ions?

• Atoms lose or gain to meet a standard—a stable energy level.

• An atom that has lost or gained electrons is called an ion. An ion is a charged particle because it now has either more or fewer electrons than protons.

Ions and Ionic Bonds• You and a friend walk past a market that sells

apples for 40 cents each and pears for 50 cents each. You have 45 cents and want an apple. Your friend also has 45 cents but wants a pear.

OK now we need learn the names of some of the most common Ions in the

world.• They come straight off the periodic

table.

Ions and Ionic

Bonds

• Ions are atoms that have lost or gained electrons.

Ions and Ionic Bonds

• Ions are atoms that have lost or gained electrons.

Fun with matching

• Matching and Concentration with Ions

Ions and Ionic Bonds• When an atom loses an electron, it loses a

negative charge and become a positive ion. When an atom gains an electron, it gains a negative charge and becomes a negative ion.

Ions and Ionic Bonds• Ionic bonds form as a result of the attraction between positive and negative ions.

Properties of Ionic Compounds• In general,

ionic compounds are hard, brittle crystals that have high melting points.

• When dissolved in water or melted, they conduct electricity.

Previewing VisualsFormation of an Ionic Bond

Q. What is an ionic bond?

A. An ionic bond is the attraction between two oppositely charged ions.Q. What is the overall charge on an ionic compound?A. Overall, an ionic compound is electrically neutral.

Salt

• Click the Video button to watch a movie about salt.

Salt Water Light

•What is electricity?

•Electricity: the movement of electrons

Salt Water Light• What happens when you put

salt into water?

• It dissolves

Salt Water Light

• If Sodium atoms and Chlorine atoms are bonded by the donated electron to make the solid

• So what happens when they dissolve?

• They are ions!

Salt Water Light

•So let’s see what happens when you lower the light bulb into the salt water.

Salt water light• How does the Salt Water allow the

electricity to flow?• The electrons flow down one Copper

Rod and are attracted to the sodium making it neutral, but the Sodium wants to get rid of the electron and it does this on the other Copper Rod. Then the electrons can light the bulb.

If two ions bonded which ones would bond?

• Positive with Negative.

Video

A Bond Forms

• A neutral atom of Aluminum has three electrons in its outer level. This is not a stable outer energy level.

• When Aluminum forms a compound with Bromine, Aluminum loses three electrons.

A Bond Forms • The Aluminum atom has become an ion.

• The aluminum now has a +3 charge.

• The 3+ charge is shown as a superscript written after the element’s symbol, Al+3 , to indicate its charge.

A Bond Forms

The electrons went to the Bromine atoms causing them to become ions too.

A Bond Forms

• This atom is no longer neutral because it gained an extra negative particle.

• It now has a charge of 1 − and is called an iodide ion, written as Br−

The Bond

• The positive Aluminum is attracted to the negative Bromide.

• The thing is that the Aluminum is 3+ and the the Bromide is only 1-

• So how many Bromide ions do we need?

• 3

So how do you write that?

• AlBr3

• Java applets with matching http://www.101science.com/chemJAVA.htm

• http://www.teacherbridge.org/public/bhs/teachers/Dana/ionic.html

• http://www.teacherbridge.org/public/bhs/teachers/Dana/ionic2.html

A Bond Forms • Notice that the resulting compound has a

neutral charge because the positive and negative charges of the ions cancel each other.

The Ionic Bond • An ionic bond is the force of attraction

between the opposite charges of the ions in an ionic compound.

The Ionic Bond

• The formation of magnesium chloride, MgCl2, is another example of ionic bonding.

• When magnesium reacts with chlorine, a magnesium atom loses two electrons and becomes a positively charged ion, Mg2+.

The Ionic Bond

• At the same time, two chlorine atoms gain one electron each and become negatively charged chloride ions, Cl −.

The Ionic Bond

• At the same time, two chlorine atoms gain one electron each and become negatively charged chloride ions, Cl −.

Zero Net Charge

• The result of this bond is a neutral compound.

• The compound as a whole is neutral because the sum of the charges on the ions is zero.

Zero Net Charge • When atoms form an ionic compound,

their electrons are shifted to the other atoms, but the overall number of protons and electrons of the combined atoms remains equal and unchanged. Therefore, the compound is neutral.

20.220.2

• Ionic bonds usually are formed by bonding between metals and nonmetals.