lesson 16: ionic bonding - chemistry with dr. james · 2019-02-11 · lesson 16: ionic bonding box...

6th Grade Lesson 16

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NOTES

Name: _________________________________________________ Date: _______________ Class: ________

Lesson 16: Ionic Bonding

Box 1:

Directions: Match the term with the correct definition / description.

1. ___ anion a. subatomic particle with no charge

2. ___ cation b. present in the outermost shell; has most energy

3. ___ electron c. calculated by subtracting total electrons – valence electrons

4. ___ neutron d. subatomic particle with +1 charge and a mass of 1 amu

5. ___ proton e. subatomic particle with -1 charge and a mass of 0 amu

6. ___ electron cloud f. an ion that has more electrons than protons

7. ___ valence electron g. the region of negative charge surrounding an atomic nucleus

8. ___ core electron h. an atom that has lost electrons

A Bohr model of a Lithium atom is drawn to the left.

A neutral atom of Li has ______ protons and ______ electrons.

Li has ______ electron shells and _____ valence electron(s).

As Li forms an ion, it will __________ electron(s) and become a(n) _____________.

A Bohr model of a Chlorine atom is drawn to the right.

A neutral atom of Cl has ______ protons and _____ electrons.

Cl has ______ electron shells and _____ valence electron(s).

As Chlorine forms an ion, it will ________________ electron(s) and become a(n) ____________________

6th Grade Lesson 16


Electrons do not just disappear and re-appear. Electrons can be _______________________________ from

_____________ atoms to _____________________ atoms, which results in formation of ________________ and

_________________________bonds.

Remember the trend of ion formation:

________________ lose electrons and _______________ gain electrons.

If a metal and nonmetal react, the ____________________ will donate electrons to

__________________ to form an _______________________ chemical bond.

Atoms gain or lose electrons so they become stable with a _________________________________ -

just like the ___________________________!

Neutral Lithium Atom Neutral Chlorine Atom

Number of p+

Number of e-

Net charge

Lithium cation Chlorine anion

Number of p+

Number of e-

Net charge

6th Grade Lesson 16


IMPORTANT FACTS:

An “ionic bond” is the result of ______________________ being _______________________________.

Ionic bonds only occur between __________________ (including ions that contain more than one atom

called _________________________________________).

Ionic bonds involve ___________________________ between __________________________________

within a ________________________________________.

Ionic bonds are also called __________________.

Ions have full ___________________________ and are ______________ just like the

________________________________.

Crystal lattice structure of salts:

Ionic compounds (salts) are neutral, which means the positive charges and negative charges must be _________.

For example, we know from looking at the _________________________________ that Lithium will form an ion

with a charge of ____________ and Chlorine will form an ion with a charge of _________.

In order for the charges to be balanced in a stable, neutral compound, _______ Li+ cation needs to be bonded to

________ Cl- anion.

6th Grade Lesson 16


Practice: Ions

DIRECTIONS: Write the ion that each neutral atom will form. Then, answer questions A and B.

1. Ca Ca2+ 3. Ba ______________ 5. Rb _____________

2. Na ______________ 4. Se ______________ 6. Br _____________

A. Of the above atoms, which will gain electrons? __________________________________________

B. Which will lose electrons? ___________________________________________________________

Writing Chemical Formulas for Ionic Compounds:

All compounds have a chemical formula which shows the ___________________ and ____________________

of atoms in it. _____________________ are always written first.

Subscripts (small numbers written to the bottom right of each element symbol) tell you the _______________

(proportion) of the elements present in a compound but not _____________________________________ or

arrangement of atoms. The subscripts are the smallest whole ratio of ions in the salt - this is called the

_______________________________________________. No subscript? Assume it’s _____________

Li3N MgCl2

VOCABULARY ALERT!!!! We refer to salts as compounds or “formula units”. Ionic compounds are the result

of giving/gaining electrons and are not “molecules”. Molecules only refer to compounds where electrons are

shared in covalent bonds (next lesson).

Practice:

1. Write the empirical formula of a compound that consists of one scandium (Sc) ion per every three

chloride (Cl) ions. __________________

2. Write the empirical formula of a compound that consists of three sodium (Na) ions per every phosphide

(P) ion. __________________

3. Write the empirical formula of a salt crystal that contains 2,000,000 cesium (Cs) ions and 1,000,000

sulfide (S) ions. __________________

Three Li+ ions One N3- ion One Mg2+ ion Two Cl- ions

There are no charges in

the chemical formula

because all the charges

added up is ZERO for

ionic compounds.

6th Grade Lesson 16


Box 2: Match the term with the correct definition / description. The definitions may be used more than once.

1. _________ sublimation A. solid liquid

2. _________ boiling B. liquid solid

3. _________ melting C. gas solid

4. _________ deposition D. solid gas

5. _________ condensation E. liquid gas

6. _________ vaporization F. gas liquid

7. _________ evaporation

8. _________ freezing

Diagraming Ionic Bonds with Bohr Models: Diagram how an ionic compound forms between two elements. Make sure your drawing is easy to understand and includes

the following:

a. each atom has correct electron shells

b. each atom has correct valence electrons

c. arrows drawn to show movement of electrons and the resulting bond

d. chemical formula for neutral compound

1. One sodium atom (Na) and one Chlorine atom (Cl).

2. One beryllium atom (Be) and two fluorine atoms (F).

6th Grade Lesson 16


Determining Empirical Formulas:

**In neutral compounds, the positive charges and negative charges must be balanced to sum up to zero.**

How many Bromide (Br) ions would it take to balance the charge of

one Potassium ion (K+)? ____________

Write the chemical formula of the compound formed between K

and Br. ____________________ **Cations are written first**

How many Chloride (Cl) ions would it take to balance the charge of

one Gallium ion? ____________

Write the chemical formula of the compound formed between Ga

and Cl. ____________________

How many Magnesium (Mg) ions would it take to balance the

charge of two Fluoride ions (F-)? ____________

Write the chemical formula of the compound formed between Mg

and F. ____________________

How many Zinc ions would it take to balance the charge of one

nitride ion? ____________

Write the chemical formula of the compound formed between Zn

and N. ____________________

6th Grade Lesson 16


How to write chemical formulas for ionic compounds:

Step 1: Write the ___________________ that the metal will form followed by the ion that the nonmetal will

form.

Step 2: Determine how to ________________________________________________ by finding the

_________________________________________________ of the charges on each ion.

Step 3: _________________________________________. Chemists talk about the _______________________

__________________________ of the ions in ionic compounds.

PRACTICE: Write the chemical formulas for compounds formed between the following elements:

EXAMPLE: Magnesium + Bromine

Ions formed: _____________________________

Chemical formula: _________________________

1. Sodium + Selenium

Ions formed: _____________________________


2. Silver + Nitrogen

Ions formed: ______________________________


3. Aluminum + Oxygen

Ions formed: ______________________________


4. Potassium + Sulfur

Ions formed: _______________________________


6th Grade Lesson 16


5. Strontium + Nitrogen

Ions formed: ________________________________


6. Barium + Sulfur

Ions formed: ______________________________


7. Gallium + Oxygen

Ions formed: ______________________________


8. Cadmium + Selenium

Ions formed: ______________________________


There are three types of chemical bonds:

Binary I Binary II Binary III

Types of

atoms

involved

Ionic bonds between two ions

(metal + nonmetal)

Metals involved: Alkali

metals, Alkaline earth metals,

Ag+, Cd2+, Zn2+, Al3+, Ga3+ In3+

Ionic bonds between two ions

(metal + nonmetal)

Metals involved: All other

metals (transition metals and

post-transition metals)

Covalent bond between two nonmetals

(electrons shared between nonmetals or

nonmetal + metalloid)

Naming

scheme:

name of metal + name of

nonmetal with “ide” ending

name of metal +

Roman numeral with charge of

cation + name of nonmetal

with “ide” ending

PREFIX*name of first element +

PREFIXname of second element with

“ide” ending

Prefixes tell you how many of each

atom is present.

*Don’t use “mono” if there is one atom

of the first element

Other

notes

Empirical formula (lowest

whole number ratio of ions in

compound only)

Empirical formula (lowest

whole number ratio of ions in

compound only)

Molecular formula (actual numbers of

each atom per molecule)

6th Grade Lesson 16


Determining Charges of Ions:

We’ve been doing Binary I thus far. Binary I compounds involve

metals from Group 1A, Group 2A, and Ag, Zn, Cd, Al, Ga, In)

Binary I metals only have ________ charge possible and you can

figure out their charge by their position on the Periodic Table.

Group 1A metals will always form __________ anions.

Group 2A metals will always form __________ anions.

The “triangle metals” form variable ions.

Binary II metals form _______________________ types of cations. For example, Iron can form Fe2+ or Fe3+ ions.

Binary II metals include all the other metals that are not Binary I.

You will need to ________________________________ to determine the charge of the cation in each compound

by finding the lowest common multiple and having the positive and negative charges add up to zero.

Practice: Balance the charges. For each salt, what is the charge of the cation?

1. Au2S

2. AuS

3. Hg3N2

4. MnCl6

+2

+3

+1

6th Grade Lesson 16


Naming Ions

Naming monoatomic cations (metals) = identified simply by the __________________________________.

Examples of cations:

Element Name of its cation

Potassium _____________________________

Lithium _____________________________

Silver _____________________________

Naming monoatomic anions (nonmetals) = (1) drop the ending of the element’s name + (2) ________________.

Examples of anions:

Element Name of its anion

Fluorine _____________________________

Nitrogen _____________________________

Oxygen _____________________________

Practice: Name the ions

Na+ = ____________________________ Cl- = ____________________________

Br- = ____________________________ I- = ____________________________

Al3+ = ____________________________ S2- = ____________________________

Box 3: Physical / chemical changes or properties?

1. A piece of iron rusting = ________________________________

2. Water evaporating = ________________________________

3. Melted wax cooling into solid wax = ________________________________

4. A candle wick burning = ________________________________

5. At room temperature, liquid nitrogen boils = ________________________________

6. Benzene-carbonic-acid is a monobasic aromatic acid, moderately strong, white crystalline powder, very soluble in

alcohol, ether, and benzene, but poorly soluble in water. = _____________________________________

7. Sodium is a soft metal that is reactive with air = _________________________________________________

6th Grade Lesson 16


Box 4: Label the arrows to name each phase change.

VOCABULARY ALERT!!!!! “mono” means one and “poly” means many.

Naming Compounds

name of metal* + name of nonmetal plus “ide” ending

PRACTICE: For each pair of elements forming an ionic bond, write its chemical formula and name. Use the

empty space to show work for balancing charges.

Empirical formula: Name:

1. Zinc + Sulfur ________________ _______________________________________

2. Calcium + Bromine ________________ _______________________________________

3. Silver + Phosphorus ________________ _______________________________________

4. Potassium + Selenium ________________ _______________________________________

5. Rubidium + Nitrogen ________________ _______________________________________

6. Aluminum + Oxygen ________________ _______________________________________

7. Sodium + Hydrogen ________________ _______________________________________

*1A metals, 2A metals, Ag, Zn, Cd, Al, In, Ga

6th Grade Lesson 16


name of metal* + Roman numeral to show the charge of the cation +

name of nonmetal plus “ide” ending

The charge of most transition metals cannot be determined simply by looking at the Periodic table. You

must balance charges because all ionic compounds are electrically neutral. The Roman numeral is only

in the name, never in the formula.

Examples:

1. Manganese (II) sulfide 2. Iron (III) chloride

Formula: ________________________ Formula: ________________________

3. If an ionic bond is formed between three iron (Fe) atoms and two nitrogen (N) atoms…

a) What is the charge of the Fe ion? ______________________

b) What is the chemical formula? ______________________

c) What is the name? ____________________________________________

4. If an ionic bond is formed between one manganese (Mn) atom and two selenium (Se) atoms…

a) What is the charge of the Mn ion? ______________________

b) What is the chemical formula? ______________________

c) What is the name? ____________________________________________

*all other metals that are not Binary I

6th Grade Lesson 16


PRACTICE: Given the empirical formulas for each compound, write the name. Use the extra space to balance

charges and determine the charge on the cation.

1. CrP ______________________________________

2. Fe2O3 ______________________________________

3. SnF4 ______________________________________

4. Cu2S ______________________________________

5. PbF2 ______________________________________

6. PbS2 ______________________________________

7. Cu3N ______________________________________

Roman numerals: I II III IV V VI VII VIII IX X

1 2 3 4 5 6 7 8 9 10

PRACTICE: Given the name of each compound, write the empirical formula. Use the extra space to balance

charges.

1. nickel (II) sulfide ______________________

2. scandium (II) chloride ______________________

3. gold (I) oxide ______________________

4. gold (II) oxide ______________________

5. lead (IV) sulfide ______________________

6. iridium (III) iodide ______________________

7. chromium (VI) nitride ______________________

6th Grade Lesson 16


Monoatomic Ions vs. Polyatomic Ions

Monoatomic ions = ___________________________________________________________________________

Polyatomic ions = ____________________________________________________________________________

Polyatomic ions are groups of covalently bonded atoms that have lost or gained electrons. They function as one

unit and do not separate during ionic bonding.

List of Polyatomic Ions you will need to memorize:

Ammonium NH4+ Carbonate CO3

2-

Hydroxide OH- Sulfate SO4

2-

Nitrate NO3- Phosphate PO4

3-

**You’ll need to memorize the formulas and charges of these so you can apply them to ionic bonding.**

Update in Naming Rules: If a compound has a polyatomic ion, use the name of the polyatomic ion (no changes).

Other notes:

When writing chemical formulas, only if there are multiple polyatomic ions per formula unit, _________

_____________________________________________________________________________________

Polyatomic anions can bond with ____________________________________________metal cations.

PRACTICE: Write the name of each compound. Watch out for Binary I vs. Binary II.

1. Li2SO4 _________________________________

2. (NH4)2S _________________________________

3. NaOH _________________________________

4. Rb3PO4 _________________________________

5. Ni(OH)2 _________________________________

6. Cr(NO3)3 _________________________________

7. MgCO3 _________________________________

8. Mn(PO4)3 _________________________________

6th Grade Lesson 16


Counting Atoms

Box 5:

Imagine you’re shooting arrows at the bull’s eye boards below. Draw “X” marks to represent arrows and match

your aim to the descriptions below each board.

2. What is the difference between “precise” measurements and “accurate” measurements?

Na2SO4 (NH4)2S LiOH Cs3PO4 Element # of atoms Element # of atoms Element # of atoms Element # of

atoms

Total Total Total Total

Co(OH)2 Fe(NO3)3 CaCO3 Cr(PO4)3 Element # of atoms Element # of atoms Element # of atoms Element # of

atoms

Total Total Total Total

6th Grade Lesson 16


Box 6: Pass around the five demo cubes (white plastic, clear acrylic, wooden, copper, and aluminum).

1. Which cube contains the most matter? _________________________________________

2. Identify which cube is more dense:

a. wooden cube vs. copper cube

b. clear acrylic cube vs. aluminum cube

c. copper cube vs. aluminum cube

3. Aluminum has a density of 2.7 g/cm3. Make your best guess for the density of copper.

a. 1.4 g/cm3 c. 8.8 g/cm3

b. 3.1 g/cm3 d. 20.1 g/cm3

4. The mass of the clear acrylic block is 16.8 g. The density of acrylic is 1.2 g/cm3. What is the volume of

the cube?

Box 7: Vocabulary – solute, solvent, solution, mixtures.

1. 40 g of sucrose was added into 500 mL of water and mixed thoroughly to make a homogeneous mixture.

a. The sucrose is the _____________________.

b. The water is the ________________________.

c. The resulting mixture is called a(n) ____________________________.

d. What do you expect this mixture to look like? _________________________________________

2. 20 mL of water was added to 980 mL of ethanol and mixed thoroughly.

a. The ethanol is the _____________________.

b. The water is the ________________________.

3. Humid air can have up to 4% water vapor.

a. The water vapor is the ______________________.

b. The air is the _________________________.

4. The _______________________ gets dissolved into the ________________________. There is always

more of the _______________________.

6th Grade Lesson 16


From the Lewis Diagrams below, write the chemical formula and name of each polyatomic ion. The lines

between the atoms represent covalent bonds (sharing of pairs of electrons between each atom).

Name: ___________________________

Chemical formula: ______________

Name: ___________________________


Name: ___________________________


Name: ___________________________


Name: ___________________________


Name: ___________________________


6th Grade Lesson 16


Given the chemical formula, write the name of each ionic compound. Remember your rules for Binary I vs.

Binary II. Use extra space at the bottom to balance charges if needed.

Binary I or II? Name:

1. Li2SO4 I II ______________________________________

2. Cd(NO3)2 I II ______________________________________

3. Co(OH)3 I II ______________________________________

4. FeBr3 I II ______________________________________

5. Cr(NO3)6 I II ______________________________________

6. TiS2 I II ______________________________________

7. YPO4 I II ______________________________________

8. AgNO3 I II ______________________________________

9. (NH4)3SO4 I II ______________________________________

10. Al2(CO3)3 I II ______________________________________

11. Pd3P2 I II ______________________________________

12. MnPO4 I II ______________________________________

When do you need to use parentheses?

When do you need to use Roman numerals?

6th Grade Lesson 16


Given the name, write the chemical formula. Remember your rules for Binary I vs. Binary II.

1. manganese (VII) oxide ___________________________

2. iron (II) iodide ___________________________

3. vanadium (V) nitrate ___________________________

4. strontium sulfate ___________________________

5. calcium carbonate ___________________________

6. copper (I) phosphate ___________________________

7. ammonium sulfide ___________________________

8. nickel (II) hydroxide ___________________________

Circle the compounds below that contain ionic bonds.

Na2SO4 CO2 LiCl CuCO3 H2O2

Sr(OH)2 RbF BF3 CH4 SO2

Properties of Ionic Compounds

Ionic compounds have _______________________________________ and _______________

___________________________ points.

o Melting = substance changes phase from a ________________ to a _______________

o Boiling = substance changes phase from a ________________ to a ________________

o Why? _____________________________________ (a lot of ___________________) is

required to overcome the ___________________________________ between cations and

anions.

o Example: Table salt (NaCl) has a melting point of __________ (1,474 °F)! Zinc chloride

(ZnCl2) has a melting point of 275 °C (527 °F) and a boiling point of 756 °C!

Ionic compounds have a _____________________________________________.

o Cations and anions ______________________ to form a three-dimensional structure.

6th Grade Lesson 16


Ionic compounds are ______________________________.

o Why? The positive cations and negative anions are ______________________________ and

____________________________________.

o Define brittle = __________________________________________________________

Ionic compounds _________________________________________________________when

___________________________________ (in ______________________________________).

o In water, the ions ______________________________ (move apart) and freely move through

the solution.

o _______________________ ionic compounds (________________________________) also

conduct electricity.

o Ionic compounds are ___________________________________.

6th Grade Lesson 16


PRACTICE: Circle the properties that are characteristic of substances containing ionic bonds.

1. low melting point

2. high melting point

3. low boiling point

4. high boiling point

5. strong bond strength

6. weak bond strength

7. sublimes at room temperature

8. liquid at room temperature

9. crystalline solid at room temperature

10. electrolyte

11. does not conduct electricity at all

12. conducts electricity when a solid

13. conducts electricity when melted

14. conducts electricity in aqueous solutions

15. soft

16. hard

17. malleable

18. brittle

19. composed of a metal and nonmetal

20. composed of two nonmetals

Box 8:

1. In the formula XSO4, the symbol X could represent the element

a. Al c. Mg

b. Ar d. Na

2. A substance changes directly from a solid to a gas during

a. deposition c. sublimation

b. saponification d. vaporization

3. What is the chemical formula for copper (II) hydroxide?

a. CuOH c. CuOH2

b. Cu2(OH) d. Cu(OH)2

4. In the ground state, all of the atoms of Period 3 elements have the same

a. atomic mass c. number of occupied energy shells

b. atomic number d. number of oxidation states

5. Element X reacts with chlorine to form an ionic compound that has the formula XCl2. To which group on

the Periodic table could element X belong?

a. Group 1 c. Group 2

b. Group 13/3A d. Group 15/5A

6th Grade Lesson 16


Box 9: Diagram how an ionic compound forms between atoms of Beryllium and Fluorine. Make sure your

drawing is easy to understand and includes the following:

a. each atom has correct electron shells

b. each atom has correct valence electrons

c. arrows drawn to show movement of electrons and the resulting bond

d. chemical formula for neutral compound

Box 10

Box 11

lesson 16: ionic bonding - chemistry with dr. james · 2019-02-11 · lesson 16: ionic bonding box...

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