Key concepts

The attractions in between the protons and electrons of atoms can cause an electron come move completely from one atom come the other. As soon as an atom loser or profit an electron, it is referred to as an ion. The atom the loses an electron becomes a positive ion.The atom the gains one electron i do not care a negative ion.A optimistic and an unfavorable ion entice each various other and form an ionic bond.

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Students will certainly look in ~ animations and also make illustrations of the ionic bonding of salt chloride (NaCl). College student will check out that both ionic and also covalent bonding start with the attractions of protons and also electrons between different atoms. However in ionic bonding, electrons space transferred indigenous one atom to the other and also not shared like in covalent bonding. Student will use Styrofoam balls to do models of the ionic bonding in sodium chloride (salt).


Students will have the ability to explain the process of the formation of ions and also ionic bonds.


Download the student task sheet, and distribute one per student when specified in the activity. The task sheet will certainly serve as the “Evaluate” ingredient of every 5-E lesson plan.


Be sure you and the student wear effectively fitting goggles.

Materials because that Each Group

Black paperSaltCup v salt indigenous evaporated saltwaterMagnifier irreversible marker

Materials for Each Student

2 little Styrofoam balls2 large Styrofoam balls2 toothpicks

Note: In one ionically external inspection substance such as NaCl, the smallest ratio of confident and an adverse ions bonded together is dubbed a “formula unit” rather than a “molecule.” Technically speaking, the term “molecule” describes two or more atoms that room bonded together covalently, not ionically. Because that simplicity, you could want to usage the hatchet “molecule” because that both covalently and ionically external inspection substances.


Show an animation to present the process of ionic bonding.

Project the animation Ionic bond in salt chloride.

Remind students that in covalent bonding, atom share electrons. But there is another form of bonding wherein atoms don’t share, but instead either take it or give up electrons. This is called ionic bonding. This animation shows a an extremely simplified version of how sodium and also chloride ions room formed.

Note: In order to simplify the version of ionic bonding, a single atom that sodium and chlorine room shown. In reality, the chlorine atom would certainly be bonded to an additional chlorine atom as part of the gas Cl2. The sodium atom would be among billions the trillions of salt atoms bonded together as a solid. The mix of this substances is a facility reaction in between the atoms of the 2 substances. The computer animation shows solitary separated atom to show the idea of just how ions and also ionic bonds space formed.

Explain what happens throughout the animation.

Tell students the the attraction the the proton in the sodium and chlorine for the various other atom’s electrons brings the atom closer together. Chlorine has actually a stronger attraction for electrons than sodium (shown by the more thick arrow). In ~ some suggest during this process, one electron from the salt is moved to the chlorine. The salt loses an electron and also the chlorine gains an electron.

Tell college student that once an atom profit or loser an electron, it i do not care an ion.

Sodium loser an electron, leave it through 11 protons, however only 10 electrons. Due to the fact that it has actually 1 more proton 보다 electrons, sodium has actually a fee of +1, making it a hopeful ion.Chlorine benefit an electron, leaving it through 17 protons and 18 electrons. Due to the fact that it has actually 1 an ext electron 보다 protons, chlorine has actually a fee of −1, making that a negative ion. Once ions form, atoms gain or lose electrons until their outer energy level is full.For example, when sodium loses its one outer electron native the 3rd energy level, the 2nd level i do not care the brand-new outer energy level and is full. Due to the fact that these electrons room closer come the nucleus, castle are an ext tightly held and also will not leave. When chlorine profit an electron, its third energy level becomes full. Second electron can not join, because it would have to come in in ~ the fourth energy level. This much from the nucleus, the electron would certainly not feel sufficient attraction indigenous the protons to it is in stable. Then the hopeful sodium ion and an adverse chloride ion entice each other and kind an ionic bond. The ion are much more stable when they space bonded than they were together individual atoms.

Have students define the process of ionic bonding in sodium chloride on their activity sheet.

Give each college student an task sheet.

Have students create a short caption under each picture to describe the procedure of covalent bonding and answer the very first three questions. The remainder of the task sheet will certainly either it is in completed as a class, in groups, or individually depending on your instructions.

Project the image Ionic link in salt chloride.

Review v students the process of ionic bonding covered in the animation.

Help students compose a quick caption next to each picture to describe the process of ionic bonding in sodium and also chloride ions.

Sodium and chlorine atoms are close to each other.The protons of the 2 atoms lure the electron of the other atom. The thicker arrowhead shows that chlorine has a more powerful attraction because that electrons 보다 sodium has.During the interactions between the atoms, the electron in sodium"s outer energy level is transferred to the outer power level of the chlorine atom.Since sodium shed an electron, it has actually 11 protons, but only 10 electrons. This renders sodium a hopeful ion with a charge of +1. Since chlorine acquired an electron it has actually 17 protons and 18 electrons. This renders chloride a an unfavorable ion with a fee of −1.The optimistic sodium ion and an unfavorable chloride ion tempt one another. They do an ionic bond and kind the ionic link NaCl.Explore

Have students observe actual salt chloride crystals and also relate their shape to the molecule model.

This two-part activity will assist students see the relationship between the setup of ion in a model of a sodium chloride crystal and also the cubic shape of genuine sodium chloride crystals.

Teacher preparation

The day prior to the lesson, dissolve around 10 grams of salt in 50 mL that water. Usage Petri bowl or usage scissors to cut down 5 or 6 clean plastic cups to do shallow plastic dishes. Pour sufficient saltwater to just cover the bottom of each dish (1 for each group). Leaving the key overnight to evaporate therefore that new salt crystals will be produced.

Materials because that each group

Black paperSaltCup v salt native evaporated saltwaterMagnifier long-term marker

Materials for each student

2 tiny Styrofoam balls2 big Styrofoam balls2 toothpicks

Procedure, part 1

Observe salt chloride crystals.Place a couple of grains the salt ~ above a item of black color paper. Use your magnifier come look closely at the salt.

Have students construct a 3-dimensional design of sodium chloride.

Each student will make 1 unit of sodium chloride. Student in each group will put their sodium chloride systems together. Girlfriend can assist the groups combine their structures right into a class model of a sodium chloride crystal.

Procedure, component 2

Make NaCl units.Use the mite to put a “−” on the large balls which stand for chloride ions.Use the mite to placed a “+” top top the small balls, which stand for sodium ions.Break 2 toothpicks in half. Use one of the half-toothpicks to attach the centers that the small and big ions with each other to do a unit of salt chloride (NaCl). Do the very same thing v the other tiny and huge ball.

Use one more half-toothpick to attach the 2 NaCl devices in a straight line as shown.

Put NaCl ions together to do one layer of ions.Contribute her line of ions to your group and also arrange them to do a 4×4 square the ions.

Use half-toothpicks to attach the end of each line to host the ion together. You only need to place toothpicks in the balls in ~ the finish of every line.

Build a course sodium chloride crystal.

Give your group’s class of ions to her teacher. Your teacher will stack these to develop a design of a salt chloride crystal.


Point out that anywhere you look at on the crystal, a salt ion and a chloride ion are constantly surrounded by the oppositely charged ion. These opposite charges organize the ions with each other in a crystal.


Ask students

Based top top the method sodium and also chloride ions bond together, why are salt crystals shaped favor cubes?The size and arrangement that the ions forms a cube ~ above the molecular level. Because the pattern repeats over and over again in the exact same way, the shape continues to be the same even when the decision becomes the normal size that we deserve to see.Extend

Show students how calcium and chlorine atoms bond to type the ionic link calcium chloride.

Tell students the there is an additional common substance referred to as calcium chloride (CaCl2). It is the salt the is supplied on icy sidewalks and roads. Explain that once calcium and chlorine react they produce ions, favor sodium and chlorine, yet the calcium ion is different from the sodium ion.

Ask students:

What ions do you think CaCl2 is made of? One calcium ion and two chloride ions.

Project the computer animation Calcium chloride Ionic Bond.

Point the end that the calcium loses two electrons, coming to be a +2 ion. Each of the 2 chlorine atom gains among these electrons, do them every a −1 ion. Assist students realize that 1 calcium ion bonds with 2 chloride ions to form calcium chloride (CaCl2), i m sorry is neutral.

Some atoms obtain or lose an ext than 1 electron. Calcium loser 2 electrons once it becomes an ion. When ions come with each other to form an ionic bond, they always join in number that precisely cancel out the positive and an adverse charge.

Project the image Calcium chloride Ionic Bond.

Review through students the process of ionic bonding covered in the animation.

Have students create a quick caption in ~ each photo to define the procedure of ionic bonding in sodium and chloride ions.

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One calcium and also two chlorine are close to each other.The protons of the calcium atom entice the electron from the chlorine atom. The proton of the 2 chlorine atoms entice the electrons from the calcium atom more strongly as presented by the more thickness arrows.During the interactions between the atoms, the 2 electrons in calcium"s outer power level space transferred come the outer energy level of each of the chlorine atoms.Since calcium lost two electrons, it has 20 protons, however only 18 electrons. This provides calcium a optimistic ion with a fee of 2+. Since each chlorine atom acquired an electron, lock each have 17 protons and 18 electrons. This provides each chloride a negative ion with a charge of −1.Oppositely charged ions lure each other, forming an ionic bond. The bonded ions are an ext stable 보다 the individual atom were.