Atomic Theory Atoms are made up of smaller particles called subatomic particles. THE MODERN VIEW OF THE ATOM It is composed of electrons, protons and neutrons ELECTRONS: Orbit the nucleus Charge of -1
Very low mass THE MODERN VIEW OF THE ATOM It is composed of electrons, protons and neutrons Protons: In the nucleus Charge of +1 Much higher mass then
electrons THE MODERN VIEW OF THE ATOM It is composed of electrons, protons and neutrons Neutrons: In the nucleus Charge of 0 Almost identical mass as
protons THE MODERN VIEW OF THE ATOM The relative size of the nucleus and atom! Atomic Theory
# of PROTONS = # of ELECTRONS in an neutral atom Nucleus Nuclear Charge Nuclear Charge = charge on the nucleus = number of protons = ATOMIC NUMBER
BLM 2-4 to 2-10 The Periodic Table Which letter(s) are missing in the periodic table? The Periodic Table
The Chemical Elements The Chemical Elements GROUPS 1 18 OR
GROUPS 1 18 OR 1A 8A + 1B 8B 3B 4B 5B 6B 7B 8B 8B 8B
1 2B B Periods (1 7) SOME GROUPS OF THE PERIODIC TABLE
The ACTUAL THE PERIODIC TABLE The Periodic Table Where are the following? Atomic number INCREASING REACTIVITY
Period Group/Family Metals Non-metals Transition metals Metalloids Alkali metals Alkaline earth metals
Halogens Noble gases Periodic Table and Ion Formation Atoms gain and lose electrons to form bonds. i.e. become positively or
negatively charged IONS Atom or a group of atoms with net negative or positive charge IONS Atom or a group of atoms with net negative or positive charge
POSITIVELY CHARGED ION = CATION NEGATIVELY CHARGED ION = ANION
Metals Metals Always form ions with a POSITIVE charge Multivalent Metals that have can lose electrons in more than Metals
one way Multivalent DO YOU KNOWMetals WHICH ONES ARE THERE? iron, cooper, vanadium, chromium, manganese, cobalt, nickel, palladium, platinum, gold, lead, tin, titanium, germanium, platinum, thallium
Non - Metals Almost always form ions with a NEGATIVE charge Non - Metals Almost always form ions with a NEGATIVE charge
WHAT NON-METAL IS AN EXCEPTION? Hydrogen BOHR DIAGRAMS There is a pattern to the arrangements of
electrons in atoms Atoms have SHELLS of electrons around the nucleus BOHR DIAGRAMS Each shell can hold a certain number of
electrons First shell: 2 electrons Second shell: 8 electrons Third shell:
Fourth shell: 8 electrons 8 electrons BOHR DIAGRAMS Diagram that shows how many electrons are in each shell
First shell: 2 electrons Second shell: 8 electrons Third shell: Fourth
shell: 8 electrons 8 electrons Patterns of Electron Arrangement in Groups If there are 8 electrons in a last shell = STABLE OCTET
Which group has a STABLE OCTET in its outer most ATOMS WANT TO HAVE A STABLE
OCTET!!!!!! ALL THE TIME!! If there are 8 electrons in a shell = STABLE OCTET All ATOMS want to be like
NOBLE GASES! Valence Shell = OUTERMOST SHELL VALENCE ELECTRONS Electrons in the VALENCE SHELL are called VALENCE ELECTRONS
How many VALENCE ELECTRONS in GROUP 1? How many VALENCE ELECTRONS in GROUP 2? How many VALENCE ELECTRONS in GROUP
16? What Do You Notice about # of Valence Electrons for Elements in the Same Group? What Do You Notice about # of Energy Levels (occupied
shells) for Elements in the Same Period? What Element is this? 18 p 22 n argon
LEWIS DIAGRAMS Show only an atoms valence electrons and the chemical symbol. LEWIS DIAGRAMS Show only an atoms valence electrons and
the chemical symbol. Rule # 1 Dots representing valence electrons are placed around the element symbols Rule # 2
Electron dots are placed singly until the fifth electron is reached then they are paired. MOLECULES and IONIC COMPOUNDS Atoms combine with different atoms to form compounds (thanks to electrons)
Forces that hold atoms together are called CHEMICAL BONDS SHARING ELECTRONS Covalent Bonds DONATING ELECTRONS
Ionic Bonds MOLECULES and IONIC COMPOUNDS Atoms combine with different atoms to form compounds (thanks to electrons)
Forces that hold atoms together are called CHEMICAL BONDS MOLECULES Covalent Bonds IONIC COMPOUNDS
Ionic Bonds MOLECULES and IONIC COMPOUNDS Atoms combine with different atoms to form compounds (thanks to electrons)
These bonds arise when VALENCE ELECTRONS interact Each atom attempts to have as many of valence electrons as the nearest noble Each atom attempts to have as many
of valence electrons as the nearest noble gas. Metals want to lose electro ns
Each atom attempts to have as many of valence electrons as the nearest noble gas. Non Metals want to gain
electro Each atom attempts to have as many of valence electrons as the nearest noble gas. 10 electrons How many
electrons does sodium, Na, want to have? Each atom attempts to have as many of valence electrons as the nearest noble gas.
10 electrons How many electrons does oxygen, O, want
IONS Atom or a group of atoms with net negative or positive charge POSITIVELY CHARGED ION = NEGATIVELY
CHARGED ION = CATION ANION IONIC COMPOUNDS Formed by an attraction of positively charged ion and negatively charged ion
Chemical formula NaCl IONIC COMPOUNDS Formed when electrons are transferred from a metal to a non - metal Chemical
formula NaCl IONS Cations and Anions are attracted to each other IONIC BONDING NaCl
IONIC COMPOUNDS Attraction between cations and anions IONIC COMPOUNDS Attraction between cations and anions IONIC COMPOUNDS Attraction between cations and anions
IONIC COMPOUNDS Draw the Bohr model diagram for KF MOLECULES and IONIC COMPOUNDS Atoms combine with different atoms to form compounds (thanks to electrons)
Forces that hold atoms together are called CHEMICAL BONDS SHARING ELECTRONS Covalent Bonds DONATING ELECTRONS
Ionic Bonds Covalent Bonds Valence Electrons are shared between atoms Covalent Bonds Valence Electrons are shared between atoms
+ hydrogen fluorine electrons are shared Hydrogen fluoride
Lewis Diagrams of IONS and IONIC BONDS For positive ions, one electron dot is removed from the valence shell for each positive charge. For negative ions, one electron dot is added to each valence shell for each negative charge. Square brackets are placed around each ion to indicate transfer of electrons.
Lewis Diagrams of IONS and IONIC BONDS For positive ions, one electron dot is removed from the valence shell for each positive charge. For negative ions, one electron dot is added to each valence shell for each negative charge.
Square brackets are placed around each ion to indicate transfer of electrons. Be
Cl
Each beryllium has two electrons to transfer away, and each chlorine can receive one more electron.
Cl
Be Cl
Since Be2+ can donate two electrons and
each Cl can accept only one electron, two Cl ions are necessary.
2+
Be Cl
Cl beryllium chloride
IONIC COMPOUNDS Draw the Lewis model diagram for K and F Ca and Cl Lewis Diagrams of COVALENT BONDS Like Bohr diagrams, valence electrons are drawn to show sharing of electrons. The shared pairs of electrons are usually drawn as a straight lineare placed around each
ion to indicate transfer of electrons. Lewis Diagrams of COVALENT BONDS LONE pair of electrons BONDING pair of electrons
Lewis Diagrams of COVALENT BONDS Draw Lewis diagram for H and O N and H C and H How many BONDING PAIRS for?
How many LONE PAIRS for? Lewis Diagrams of COVALENT BONDS Draw Lewis diagram for H and O N and H C and H
Lewis Diagrams of COVALENT BONDS Diatomic molecules, like O2, F2 or N2 are also easy to draw as Valence electrons are Lewis diagrams. shared Several non-metals join to form diatomic molecules.
Lewis Diagrams of COVALENT BONDS Draw LEWIS STRUCTURE of O2 O O O O
O O DOUBLE BOND Lewis Diagrams of COVALENT BONDS Draw LEWIS STRUCTURE of N2
N N N N N N TRIPLE BOND Lewis Diagrams of COVALENT BONDS
Draw LEWIS STRUCTURE of CO2 C O O O C O O C O
