lesson 17: technicolor atoms - de la salle high school€¦ · what evidence is there that certain...

ChemCatalyst

These drawings are models that show solid copper, solid copper chloride, and aqueous copper chloride as collections of atoms.

1. Describe each model.

2. What is similar about each model? What is different?

Cu(s)

Solid copper

CuCl2(s)

Solid copper (II) chloride

CuCl2(aq)

Aqueous copper (II) chloride

Lesson 17: Technicolor Atoms

What evidence is there that certain atoms are present in a

compound?

By the end of today, you will be able to….

conduct a flame test and use the results to determine the

identity of a compound

interpret evidence of the presence of certain atoms within

compounds


Flame test: A test used in the laboratory to look for the presence of certain metal

atoms. A sample of a compound is heated in a flame, and the resulting color is noted.

In the Lab, reminders…

You will be using chemicals and fire today. Follow safety instructions.

Wear safety goggles.

Tie back long hair and remove dangling jewelry.

Roll up long sleeves and keep clothing away from flames.

Leave lab performance sheet at your station for a stamp today. Reminder – sheets need to be filled out completely.

Always exhibit safe behavior and clean lab stations before you leave!!


Notes

The metal element in each chemical formula appears to be responsible for the flame colors.

Only certain elements produce colorful flames.

Flame test: A test used in the laboratory to look for the presence of certain metal atoms. A sample of a compound is heated in a flame, and the resulting color is noted.

What are elements/compounds?

1. What do you notice about the number of spokes on the circles?

2. The spokes represent electrons. Do the spokes represent the total number of electrons? Explain your thinking.

**Review: Predict the flame color

produced when heating these

substances. Explain your thinking.

copper (II) carbonate

calcium chloride

IV - Lesson 18: Life on the Edge

ChemCatalyst

Sodium Atom, Na


Notes

Flame colors are associated

with movements of the electrons

within the sodium atom.

Bohr’s Model/

Shell model

The Shell Model

The surface of each sphere

represents an area where an

electron or a group of electrons

is most likely to be found.

Lesson 18: Life on the Edge

Notes

Electron shells are the levels around the nucleus

where electrons might be found.

Sodium and magnesium have electrons in three electron shells.


Notes

How does an element’s position on the periodic table determine the

arrangement of an element’s electrons?

G

R

O

U

P

S

Rows or periods


Notes

There are patterns in the way electrons are arranged related to

the position of the element on the periodic table.

Atomic number = proton # = total # of electrons


Notes

There are patterns in the way electrons are arranged related to

the position of the element on the periodic table.

Group # of element = # of electrons in the outermost shell

I

II III IV V VI VII

VIII


Notes

Row of element = # of electron shells

Row

1

2

3

4


Notes

The first shell can hold up to 2 electrons.

The second shell can hold up to 8 electrons


Notes

Draw an atom with 3 shells and 2 electrons in its outermost shell.

What element is this?


Notes

The electrons in the outermost shell are called valence electrons.

Core electrons

Valence electrons

The electrons in the inner shells are called core electrons.


Notes

IV-Lesson 19: Noble Gas EnvyChemCatalyst

Chemists have found that metal atoms transfer electrons to nonmetal atoms when they form compounds. Examine the shell model showing how a lithium atom might transfer an electron to a fluorine atom.

1. What effect does this electron transfer have on the charge of each atom?

2. What element does each atom resemble after the electron has been transferred?

Provide each piece of information for element 34.

a. The element’s name and symbol.

b. The total number of electrons in an atom of this element.

c. The number of core electrons in an atom of this element.

d. The number of valence electrons.

e. The group number for this element.

f. The names of other elements with the same number of valence electrons.


Check-In

Ion: An atom that has

acquired a net electric

charge by gaining or losing

one or more electrons.

What happens when atoms form ions?

IV-Lesson 19: Noble Gas Envy

Notes

When electrons are removed from or

added to an atom, the rest of the atom

stays the same.

1) Number the cards1-20 then 31-36.

2) Shuffle the cards, then deal to your team.

3) The number of the cards you get is the atomic

number. Create cards like the ones shown.

8


Activity

IV-Lesson 20: Getting Connected

ChemCatalyst

Metal elements combine with the nonmetal element chlorine, Cl, to form compounds. The formulas are given in the tables.

1. Compare the three tables. What do you notice? (check periodic table)

2. Predict the formula of a compound formed between lithium, Li, and chlorine, Cl. Which table would you put it in?

Element Compound

Na NaCl

K KCl

Element Compound

Mg MgCl2

Ca CaCl2

Element Compound

Ne none

Ar none

Over Weekend:

Get caught up with

textbook questions!

The Ion Card Table


Notes

Electron arrangements

of atoms in ionic

compounds resemble

noble gases.

Atoms tend to lose or gain

electrons to attain the electron

arrangement of a noble gas.


Notes

+1

+2 +3 +4 -3 -2 -1

0

1e-

2e- 3e- 4e- 5e- 6e- 7e-

8e-

Key:

# valence electrons

cation charge

anion charge


Add Info to your Table

1. Draw a shell model for calcium, Ca, showing the

arrangement of its electrons.

2. What would have to happen for an atom of calcium to

have an electron arrangement like that of a noble gas?

Explain.


Check-In

How is chemical stability related to the arrangements of electrons in atoms?

When atoms gain or lose electrons, they form ions. Ions are atoms that carry a net positive or net negative charge.

When atoms lose electrons, they have a positive charge and are called cations.

When atoms gain electrons, they have a negative charge and are called anions.

Ions have electron arrangements resembling those of the noble gas atoms.


Wrap-Up


ChemCatalyst

Metal elements combine with the nonmetal element chlorine, Cl, to form compounds. The formulas are given in the tables.

1. Compare the three tables. What do you notice? (check periodic table)

2. Predict the formula of a compound formed between lithium, Li, and chlorine, Cl. Which table would you put it in?

Element Compound

Na NaCl

K KCl

Element Compound

Mg MgCl2

Ca CaCl2

Element Compound

Ne none

Ar none

Over Weekend:

Get caught up with

textbook questions!

• Metal atoms and nonmetal atoms combine to form

ionic compounds.

How can valence electrons be used to predict chemical formulas?

Examples: NaCl, MgCl2

metals:

non-metal:


Notes

Combine magnesium, Mg, and chlorine, Cl, into an ionic

compound so that each ion resembles a noble gas.

Mg

Cl

Cl


Notes

Mg2+ + Cl– + Cl– produces MgCl2 with zero charge.


Notes

• In ionic compounds the metal is considered the cation

and the nonmetal is considered the anion.


Example: NaCl, MgCl2

Mg2+ is the ______, Cl- is the ______.

Na+ is the ______, Cl- is the ______.

+ -


Notes

Metal atoms and nonmetal atoms combine in ratios that

result in a total of 8 or a multiple of 8 valence electrons.



Notes

The charges on the cations and anions in ionic

compounds add to zero.


Examples: Na+ and Cl- form NaCl

( Na+ + Cl- = 0 )

Mg2+ and Cl- form MgCl2

( Mg2+ + Cl- + Cl- = 0)


Notes

F O N

Li

Chemical Formula_______

________ _______

Mg

_______Chemical Formula______

______

Al

_______Al2O3

________

On a full page, make the following table. Draw the ions and compounds.


Notes

Use your periodic table to write the correct chemical

formula of 3 ionic compounds formed from the

following elements:

Sr K S H Br


Check-In

Wrap Up


Metal atoms and nonmetal atoms combine to form ionic compounds.

In ionic compounds, the metal is considered a cation, and the nonmetal is considered an anion.

The charges on the cations and the anions in ionic compounds sum to 0.

Metal atoms and nonmetal atoms usually combine in ratios that result in a total of eight valence electrons or a multiple of eight valence electrons.

Check-in

What elements will combine with strontium, Sr,

in a 1:1 ratio? Explain your thinking.

1. List the ionic compounds you can make with 2 cards, using 2 different elements.

2. List the ionic compounds you can make with 3 cards and only 2 different elements.

3. What rule must all these compounds satisfy?

IV-21: Salty EightsChemCatalyst

Reminder:

Our focus is

valence electrons

Chemical Formulas of Ionic Compounds

Example

Number of

valence

electrons for

the metal

Number of

valence

electrons for

the nonmetal

Total

number of

valence

electrons

Total

positive

charge

Total

negative

charge

Total charge

NaF 1 7 8 +1 –1 0

MgO 2 6 8 +2 –2 0

MgCl2 2 7 16 +2 2(–1) 0

K2Se 1 6 8 2(+1) –2 0

AlN 3 5 8 +3 –3 0

Al2O3 3 6 24 2(+3) 3(–2) 0

AlF3 3 7 24 +3 3(–1) 0


Work Check

Naming ionic compounds:

Metal then non-metal.

Change the ending of the non-metal to –ide.

Examples: Na2O

sodium oxide

MgCl2magnesium chloride


Notes

Predicting chemical formulas & naming ionic compounds.

IV-21: Salty EightsThe Game

5 points for every noble gas

10 points for every compound made out of two cards

40 points for every compound made out of three cards

70 points for every compound made out of four cards

100 points for every compound made out of five cards

20 points for going out first

IV-21: Salty EightsScoring the Game

Rules on Back of handout

In general, atoms come together to form an ionic

compound if the number of valence electrons totals 8 or

a multiple of 8.

IV-21: Salty EightsNotes

Writing correct chemical formulas is a matter of keeping track

of exactly how many atoms come together to make a

compound.

IV-21: Salty EightsNotes

How can you predict chemical formulas and name ionic

compounds?

Ionic compounds tend to form from atoms that together have a

total of 8 (or a multiple of 8) electrons in their outermost

(valence) shells.

Noble gases already have eight valence electrons and don’t

combine with other elements to make new compounds. They

are already highly stable.

IV-21: Salty EightsWrap-Up

Which of these compounds are likely to form?

a. Na2S b. K2Mg c. AlBr2

d. Na3N e. OCl f. CaO

IV-21: Salty EightsCheck-In

IV-22 Isn’t it Ionic? – Polyatomic Ions

ChemCatalyst

The cards show a sodium ion and three polyatomic ions.

1. What do you think a polyatomic ion is?

2. Name three compounds formed between sodium ions and each

of the three polyatomic ions. Use the rule of zero charge to write

the compounds’ formulas.

Ionic compound: An ionic compound is a compound

composed of positive and negative ions, formed when

metal and nonmetal atoms combine.

IV-22 Isn’t it Ionic?Review

Polyatomic Ions ~ “many atom ion”

IV-22 Isn’t it Ionic?Notes

Polyatomic ion: Ions composed of several different

atoms. These atoms stay together as a group. The

charge is shared amongst all of the atoms.

Most polyatomic ions are anions.

The rule of zero charge can be used to predict the

formulas of compounds that contain polyatomic ions.


Compounds containing polyatomic ions have their

own unique naming guidelines.

Polyatomic ion Name

OH– hydroxide

NO3– nitrate

CO32– carbonate

SO42– sulfate

NH4+ ammonium

IV-22 Isn’t it Ionic?Notes – Polyatomic Ions

What is a polyatomic ion?

Polyatomic ions are ions composed of a group of

atoms. The charge is shared by all the atoms.

To write the formula of an ionic compound that

contains polyatomic ions, use the rule of zero

charge.

When naming compounds containing

polyatomic ions, simply insert the name of the

ion.


1. What is the name of the compound Be(NO3)2?

2. What ions are present in this compound, and

what are the charges on the ions?

IV-22 Isn’t it Ionic?Check-In

IV23: Alchemy of PaintTransition Metal Chemistry

Transition Metals tend to be brightly colored –

common found as pigments

Ex: Blue – cobalt blue – cobalt (II) oxide

To determine the charges on transition metal cations:

1. Determine the ion charge that you do know

2. Apply the rule of zero charge

FeO

Cation: ____ Anion: ____

Transition Metal CompoundsPractice – In your binder

Chemical Name Chemical Formula Cation Anion

Cobalt (II) oxide

Fe2O3

Cr 3+ O 2-

Manganese (IV) dioxide MnO2

Copper (I) oxide

Silver sulfide Ag2S

Fe(NO3)3

Copper (II) carbonate Cu 2+

Most transition metals can form

several ions with different charges

describe the structure of an atom in terms of electron shells

and subshells

use the periodic table to determine the electron arrangement

in an atom and to write electron configurations

explain the organization of the periodic table in terms of the

arrangements of electrons in subshells

IV 24: Shell Game – Electron Configurations

Goals

These drawings show two different ways to represent the arrangement of the electrons in atoms of the element calcium, Ca.

1. Name at least two differences in the drawings.

2. Name at least two similarities in the drawings.


ChemCatalyst

The electron shells in the shell model of an atom are divided into subshells (except for the first shell, n=1).

Shell Number of electrons in the shell Subshell Number of electrons in the subshell

n = 1 2 1s 2

n = 2 8

2s

2p

2

6

n = 3 18

3s

3p

3d

2

6

10

n = 4 32

4s

4p

4d

4f

2

6

10

14


Notes

The periodic table is organized in subshell blocks.


Notes

Electron configuration: A shorthand way to keep track of all the electrons in an atom of an element for all the subshellsthat have electrons.


NotesNo chemcatalyst today

1s2 2s2 2p6

Shell #Subshell Letter

# of electrons in

the shell

What element does this electron

configuration code for??

The order of filling subshells does not always correspond to

the numerical order of the subshells. (4s2 3d10)

The elements in the different subshell blocks have related

properties.

Chemists keep track of electrons and the subshells they are in

by writing electron configurations.


Notes

Identify the element with this electron configuration:

1s22s22p63s23p64s23d104p3


Check-In

Wrap Up

What does the periodic table indicate about the arrangements of electrons?

Each electron shell in the shell model, except for n = 1, is divided into subshells.

Each subshell can hold a specific maximum number of electrons.

The periodic table can assist you in figuring out the placement of electrons in subshells.

Chemists keep track of electrons and the subshells they are in by writing electron configurations.

lesson 17: technicolor atoms - de la salle high school€¦ · what evidence is there that certain...

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