Atoms & Chemical Bonding Created in 2008 by Tim F. Rowbotham, Modified in 2011

Element Cards Follow the directions in the following slides to complete this journal

Atoms & Chemical Bonding Created in 2008 by Tim F. Rowbotham, Modified in 2011

NOTES

Valence Electrons Electrons in the outermost energy level are known as valence electrons. Valence electrons are important because they are the only ones involved in chemical bonding.

Valence Electrons Valence electrons can be gained, lost, or shared by atoms during chemical bonding. This desire for a certain amount of valence electrons is what causes chemical reactions.

Valence Electrons How many valence electrons in this atom? REMEMBER VALENCE ELECTRONS ARE ONLY THOSE IN THE OUTER ENERGY LEVEL

How many valence electrons in this atom?

How many valence electrons in this atom?

How many valence electrons in this atom?

How many valence electrons in this atom?

Return your remote Complete p. 6-7 of your packet Created in 2008 by Tim F. Rowbotham, Modified in 2011

Entrance Questions Ready your remote Created in 2008 by Tim F. Rowbotham, Modified in 2011

How many valence electrons in this atom?

How many valence electrons in this atom?

How many valence electrons in this atom?

How many valence electrons in this atom?

CHEMICAL BONDING NOTES Turn to page 1 of your CHEMICAL BONDING PACKET

Rows on the Periodic Table Rows across the periodic table are known as periods. Elements in the same row have the same number of energy levels. This outer energy level is often referred to as the valence energy level or the valence shell.

Families on the Periodic Table Elements in the same column of the periodic table are known as groups or families. Elements in the same family have the same number of valence electrons.

Families & Properties Since elements in the same family have the same number of valence electrons, they behave very similarly in a chemical reaction. Therefore, atoms in the same family have very similar properties!!!

Using the Periodic Table How to Determine the Number of Valence ElectronsHow to Determine the Number of Valence Electrons

Learning Checks Ready your Remotes

Columns on the periodic table are called 1.Periods 2.Groups 3.Compounds 4.Bonding Reagents

What is true of elements in the same column of the periodic table? 1.Same first letter 2.Similar properties 3.Same number of protons as neutrons 4.Discovered in the same year

Rows on the periodic table are called 1.Groups 2.Compounds 3.Periods 4.Bonding reagents

What is the valence energy level of strontium (A# = 38) ? 1.2 nd 2.3 rd 3.4 th 4.5 th

What is the valence energy level of Mercury (A# = 80) ? 1.3 rd 2.4 th 3.5 th 4.6 th

How many valence electrons does bromine have(A# = 35) ?

How many valence electrons does phosphorus have(A# = 15) ?

What is the valence energy level of calcium (A# = 20) ? 1.1 st 2.2 nd 3.3 rd 4.4 th

How many valence electrons does calcium have(A# = 20) ?

Electron Dot Diagrams Since only the valence electrons are involved in chemical bonding, chemists have a quicker, easier way to represent atoms when showing bonding called an electron dot diagram.

Electron Dot Diagrams An electron dot diagram is simply the chemical symbol of an element with 1 dot for every valence electron it has. This is also referred to as a Lewis dot structure.

Sample Dot Diagrams

Learning Checks Ready your Remotes

Rows on the periodic table are called 1.Groups 2.Compounds 3.Periods 4.Bonding reagents

What is true of elements in the same column of the periodic table? 1.Same first letter 2.Similar properties 3.Same number of protons as neutrons 4.Discovered in the same year

Using the Periodic Table Return Your Remote Pick up & Complete Electron Dot diagrams WS Complete PACKET p.8 “Properties of a Missing Element”

Using the Periodic Table Valence Electrons, Lewis Dot Diagrams & Bohr ModelsValence Electrons, Lewis Dot Diagrams & Bohr Models

Entrance Questions Ready your Remotes Get out a periodic table

Columns on the periodic table are called 1.Periods 2.Groups 3.Compounds 4.Bonding Reagents

How many valence electrons does aluminum have(A# = 13) ?

What is the valence shell of aluminum (A# = 13) ? 1.1 st 2.2 nd 3.3 rd 4.4 th

How many valence electrons does phosphorus have(A# = 15) ?

Columns on the periodic table are called 1.Periods 2.Families 3.Compounds 4.Bonding Reagents

What is true of elements in the same column of the periodic table? 1.Same first letter 2.Similar properties 3.Same number of protons as neutrons 4.Discovered in the same year

How many valence electrons does chlorine have(A# = 17) ?

Chlorine-37 would have how many neutrons? (A#17)

How many valence electrons does phosphorus have (A# = 15) ?

Exit Questions Return your Remotes Read Text pages (Chapter 5.2) Complete Periodic Table Brochure Complete pages 8–10 of Chem Bonding Pack

Entrance Questions Ready your Remotes Get out a periodic table

Oxygen-17 would have how many neutrons? (A#8)

What is true of elements in the same column of the periodic table? 1.Same first letter 2.Similar properties 3.Same number of protons as neutrons 4.Discovered in the same year

How many valence electrons does magnesium have (A# = 12) ?

How many energy levels does magnesium have (A# = 12) ?

Entrance Questions Return your Remotes Turn in Periodic Table Brochure Read Text pages (Chapter 5.3) 5.3 Representative Groups Reading Organizer Answer Assessment Questions 1-11 Complete pages 9–16 of Chem Bonding Pack ADD- Valence Electrons, Valence Shells, and Electron Dot Diagrams to the flip chart.

Entrance Questions Ready your Remotes

Which of the following elements has 6 valence electrons? 1.Oxygen (A# 8) 2.Neon (A# 10) 3.Lithium (A# 3) 4.Carbon (A# 6)

CHEMICAL BONDING NOTES Turn to page 2 of your CHEMICAL BONDING PACKET

Stable Atoms Chemically stable atoms have 8 valence electrons (Octet Rule) (Atoms with only 1 energy level can be stable with only 2 valence electrons)

Which of the following elements is naturally chemically stable? 1.Oxygen 2.Neon 3.Lithium 4.Carbon

Which of the following families have elements that are chemically stable? 1.Alkali metals 2.Alkaline earth metals 3.Halogens 4.Noble Gases

Chemical Bonding Atoms chemically bond or react to become stable atoms. They can do this by gaining, losing, or sharing valence electrons.

Nerdy electrons? Use the nerds on the Energy Level Diagrams to represent electrons in the energy levels of the neutral atoms in the slides that follow:

Nerdy electrons? Fluorine (A#9)

Nerdy electrons? Fluorine – using the nerds to represent electrons, show the proper location of fluorine’s 9 electrons in its energy levels

Nerdy electrons? Fluorine (A#9)

Nerdy electrons? Fluorine: What change would make it chemically stable?

Nerdy electrons? Fluorine: Adding 1 more valence electron would give it a stable 8 !!! --

Nerdy electrons? Fluorine: What effect does this have on the fluorine atom? --

Nerdy electrons? Fluorine: NOW HAS A CHARGE OF -1 It is now chemically stable!!! --

Nerdy electrons? Sulfur (A#16)

Nerdy electrons? Sulfur – using the nerds to represent electrons, show the proper location of sulfur’s 16 electrons in its energy levels

Nerdy electrons? Sulfur (A#16)

Nerdy electrons? Sulfur: What change would make it chemically stable?

Nerdy electrons? Sulfur: Adding 2 more valence electrons would give it a chemically stable 8 !!! --

Nerdy electrons? Sulfur: What effect does this have on the fluorine atom? --

Nerdy electrons? Sulfur: IT NOW HAS A CHARGE OF -2 It is now chemically stable!!! --

Nerdy electrons? Sodium (A#11)

Nerdy electrons? Sodium – using the nerds to represent electrons, show the proper location of sodium’s 11 electrons in its energy levels

Nerdy electrons? Sodium (A#11)

Nerdy electrons? Sodium: What change would make it chemically stable?

Nerdy electrons? Sodium: Adding 7 more valence electrons would give it a chemically stable 8 !!! --

Nerdy electrons? Sodium: But… is there an easier way? --

Nerdy electrons? Sodium: Take a look again. Is there a different way to get 8 valence electrons?

Nerdy electrons? Sodium: Losing 1 electron would leave 0 in the 3 rd energy level, making the 2 nd energy level the valence shell… which would now have a chemically stable 8!!!

Nerdy electrons? Sodium: NOW HAS A CHARGE OF +1 !!! It is chemically stable.

Nerdy electrons? Other examples:

Nerdy electrons? Magnesium (Construct if you have pink nerds) Oxygen (Construct if you have purple nerds)

Nerdy electrons? So… where do atoms pick up extra electrons?

Nerdy electrons? - -

From other atoms that want to lose them!!!

Ions When an atom gains or loses electrons to become stable, it is called an ion. An ion is a charged atom.

Positive Ions Atoms that lose electrons become positively charged. These positive ions are called cations.

Negative Ions Atoms that gain electrons become negatively charged. Negative ions are called anions.

Ionic Bonding Atoms looking to be stable may transfer electrons to other atoms. Each atom becomes charged, and positive ions are then attracted to negative ions.

Ionic Compounds The attraction of positive ions to negative ions is called an ionic bond. Atoms that bond this way are called ionic compounds.

Ionic Compounds Here’s how it happens: Ionic Bond Video Clip 11 Ionic Bond Video Clip 22 Ionic Bond Video Clip 33

Ionic Bonding

Learning Checks Ready your Remotes

Atoms that gain or lose electrons in order to become more chemically stable are called 1.Isotopes 2.Ions 3.Radioactive 4.Neutral

What would a chlorine atom do to become chemically stable? (A# = 17) 1.Gain 1 electron 2.Lose 1 electron 3.Gain 2 electrons 4.Lose 7 electrons

What would an iodine atom do to become chemically stable? (A# = 53) 1.Gain 1 electron 2.Lose 1 electron 3.Gain 2 electrons 4.Lose 7 electrons

Learning Checks Return your Remote Complete PACKET pages Ionic Bonds

Learning Checks Ready your Remotes

How many valence electrons does rubidium have(A# = 37) ?

Stable atoms have how many valence electrons?

What would a rubidium atom do to become chemically stable? (A# = 37) 1.Gain 1 electron 2.Lose 1 electron 3.Gain 2 electrons 4.Lose 3 electrons

Learning Checks Return your Remotes

Learning Checks Ready your Remotes

Stable atoms have how many valence electrons?

How many valence electrons does potassium have(A# = 19) ?

What would a potassium atom do to become chemically stable? (A# = 19) 1.Gain 1 electron 2.Lose 1 electron 3.Gain 2 electrons 4.Lose 3 electrons

Atoms that gain or lose electrons in order to become more chemically stable are called 1.Isotopes 2.Ions 3.Radioactive 4.Neutral

JOURNAL#2 Draw electron dot diagrams of Fluorine, Chlorine, Bromine, & Iodine

Learning Checks Ready your Remotes

How many valence electrons does sulfur have(A# = 16) ?

Stable atoms have how many valence electrons?

What would a sulfur atom do to become chemically stable? (A# = 16) 1.Gain 2 electrons 2.Lose 2 electrons 3.Gain 3 electrons 4.Lose 3 electrons

Oxidation Numbers Turn to page 3 of your packet

Oxidation Number The oxidation number is essentially the bonding power of an atom. The oxidation number of an atom is the charge that it will tend to acquire when bonding.

Oxidation Number A positive oxidation number means that an atom will lose electrons when forming an ionic bond. A negative oxidation number means that it will gain electrons.

Sample Oxidation Numbers Chlorine:- 1 Sodium:+1 Calcium:+2 Sulfur:- 2 Aluminum:+3

Video Clips Intro to Bonding (Ionic) 4:304:30 Valence electrons 2:462:46

Learning Checks Ready your Remote

How many valence electrons does phosphorus have(A# = 15) ?

What would a phosphorus atom do to become chemically stable? (A# = 15) 1.Gain 2 electrons 2.Lose 2 electrons 3.Gain 3 electrons 4.Lose 3 electrons

What is the oxidation number of phosphorus? (A# = 15)

What is the oxidation number of nitrogen? (A# = 7)

What is the oxidation number of chlorine? (A# = 17)

What is the oxidation number of magnesium? (A# = 12)

Learning Checks Return your Remote Complete the “Periodic Table Perspectives” sheet

Video Clips Element Rap 3:003:00 The Noble Gas Song 3:283:28 The Noble Gas Rap 2:502:50

Entrance Questions Ready your remote

How many valence electrons does an arsenic atom have? (A# = 33)

What is the oxidation number of arsenic? (A# = 33)

How many energy levels does an arsenic atom have? (A# = 33)

Changing An Atom RETURN YOUR REMOTE Turn to page 19 of your packet & complete it Pick up a copy of the “Families of the Periodic Table” worksheet

Video Clips Families of the Periodic Table 14:4214:42 Groups of Elements on the Periodic Table 7:267:26

Video Clips Alkali Metals in Water 2:222:22 Sodium & Potassium in Water 0:530:53 The Halogens 3:403:40

Learning Checks Ready your Remote Get ready to consult your periodic table!!

What is the oxidation number of strontium? (A# = 38)

What is the oxidation number of oxygen?

What would a calcium atom do to become chemically stable? (A# = 20) 1.Gain 1 electron 2.Lose 1 electron 3.Lose 2 electrons 4.Gain 2 electrons

In a chemical reaction, what would an oxygen atom do? 1.Gain 1 electron 2.Lose 1 electron 3.Gain 2 electrons 4.Lose 2 electrons

Learning Checks Return your remote Turn to page 20 of your PACKET Make sure you finish page 20 – 21 “Bonding Basics – Ionic Bonds”

Covalent Bonding When atoms share electrons to become stable, it is called a covalent bond. Covalently bonded atoms are called molecules.

Sample Molecule Hydrogen Fluoride BeforeAfter  HF

Sample Molecule Ammonia BeforeAfter  NH 3

Sample Molecule Oxygen (diatomic molecule) BeforeAfter  O 2

Video Clips The Bonding Song 4:194:19

Polyatomic Ions Polyatomic ions are covalently bonded atoms that still hold a positive or negative charge. Sometimes called radicals, these molecules act as one and can form ionic compounds.

Common Polyatomic Ions AmmoniumNH 4 +1 AcetateC 2 H 3 O 2 -1 HydroxideOH -1 NitrateNO 3 -1 CarbonateCO 3 -2

Law of Conservation of Matter The Law of Conservation of Matter states that matter is neither created nor destroyed in a chemical reaction. Matter can just change from one form to another.

Law of Conservation of Matter The mass of the reactants is equal to the mass of the products of a chemical reaction. The number of atoms before a chemical reaction is the same as the number after a chemical reaction.

Law of Conservation of Matter REACTANTSPRODUCTS

Law of Conservation of Matter REACTANTSPRODUCTS4 H2 O BALANCED CHEMICAL EQUATION: 4 H O 2  2 H 2 O

Law of Conservation of Matter REACTANTSPRODUCTS

Law of Conservation of Matter REACTANTSPRODUCTSTOTAL ATOMS2 H2 Cl BALANCED CHEMICAL EQUATION: H 2 + Cl 2  2 HCl TOTAL MASS: 2 (1.0g) + 2 (35.5 g) = 2 (36.5 g) g = 73.0 g

The Law of Conservation of Matter BALANCED CHEMICAL EQUATION: Na 2 SO 4 + Ca Cl 2  CaSO NaCl

The Law of Conservation of Matter

27 grams of aluminum react with 24 grams of oxygen. What mass of aluminum oxide forms? 1.27 grams 2.24 grams grams 4.51 grams

What coefficient should go in front of the H 2 to properly balance this equation? 2 H 2 O  ? H 2 + O

Law of Conservation of Matter Video 11 Homer & Conservation of Mass 22 Antoine Lavoisier's Discovery 33

Bibliography Bohr Models from