Bonds and Orbitals

What does Ionization Energy Look like

What requires more energy, removing valence or core electron

Core electron

What are the core and valence removal exceptions

• Filled ns² is more stable than np¹ Be vs B

• Half filled np³ have added stability N vs O

• Half filled d⁵ or filled d¹⁰ orbitals are stable

How does Effective Nuclear Charge look like

What is Effective Nuclear Charge

The actual attractive force electrons encounter. Outermost electrons feel the effective nuclear charge

How does Atomic Radius look like

Why does Atomic Radius increase down the perioc table

Nucleus stays the same size, but electron cloud gets larger because of more electrons

What is Electron Affinity

Energy change when an electron is added to an atom in the gas phase. Greater electron affinity means more energy released when electrons are added.

What does Electron Affinity look like

What is Electronegativity

Reflects an element’s capacity to attract shared electrons to itself

What does High Electronegativity mean

• High Ionization Energy

• High Affinity for additional electrons

What does Electronegativity look like

What is similar in the Periodic Group

Same Valence Electron Configuration

What is similar in Periodic Row

Change Monotomically

What doe metals for in nature

Cations

What do Nonmetals trend towards in nature

Anionic character

What is Bonding

When electrons are attracted to each other and form a bond when they get close to each other

What happens to Energy during Bonding

Potential Energy decreases. More stability, Energy is released.

What is the Difference in Electronegativity range/Percentage ionic character for Ionic Bonds

3.3 to 1.7 or 100% to 50%

What is the Difference in Electronegativity range/Percentage ionic character for Polar-Covalent Bonds

1.7 to 0.3 oe 50% to 5%

What is the Difference in Electronegativity range/Percentage ionic character for NonPolar-Covalent Bonds

0.3 to 0 or 5% to 0%

How do you calculate Difference in Electronegativity for bonds

Find change in electronegativity:

Cl 3.0 - Na 0.9 = 2.1, Ionic

O 3.5 - H 2.1 = 1.4 Polar Covalent

C 2.5 - H 2.1 = 0.4 Non Polar Covalent

What is an Ionic Bond

Bonds between ions where one atom gains electrons and the other loses electrons

What is Electrostatic Attraction

Positive to Negative Charges

Which Bond forms a strong lattice

Ionic Bond

What is Coloumbs Law

What is a Metallic Bond

Electrons are delocalized sea around an ordered array of metal cations. Valence electrons dont belong to any single nucleus but are shared throughout metal

What are Atomic Interactions

Potention energy from proton, electron attractions, and electron

Minimum energy when forces are balanced, bond length

What are Covalent Bonds

Electrons are shared by nuclei, nonmetals, energy of atoms bonded together is lower than E of them apart so bond forms. Nonpolar and Polar

What is Nonpolarity

Share valence electorns equally, so no poles

What is Polarity

Share electrons unequally, so positive and negative poles

What is a Dipole Moment

Measures how unevenly electrons are shared between the atoms in the molecule. It is the separation of postivie and negative electrical charges within a system

What are the rules for Bond Length and Strength

Multiple bonds are shorter and stronger than single bonds

F-F < O=O < N≡N

What are the rules for Dot Structure

1. Count Valence electrons

2. Set up molecules with the least electronegativity in the middle

3. Add electrons

4. If no electrons remain, move lone pairs to make multiple bonds

5. Write Formal Charge

6. Check structure

What is Formal Charge

Informs on how many bonds an element is likely to make in a structure

How do you calculate Formal Charge

Valence Electrons - # Unshared Electrons - # Bonds

What is Resonance

When more than one dot structure can be written

The real structure is an average of all resonance forms, with electons delocalized across the bodns with resonance

What are the Electron defficient Molecules

H —> 2 electrons

B —> 6 electrons

Which Atoms can have expanded octets?

3rd Row Elements or Larger

What is an Odd Electron Species

Free Radical that should be placed on least electronegative species

What is Valence Shell Electron Pair Repulsion

It describes the shapes of molecules

What are the Electron Domain Geometries

2. Linear

3. Trigonal Planar

4. Tetrahedral

5. Trigonal Bipyramidal

6. Octahedral

What are the SN and Bond Angles of Linear

SN=2 180

What are the SN and Bond Angles of Trigonal Planar

SN=3 120

What are the SN and Bond Angles of Tetrahedral

SN=4 109.5

What are the SN and Bond Angles of Trigonal Bipyramidal

SN=5 90, 120, 180

What are the SN and Bond Angles of Octahedral

SN=6 90, 180

What are the Molecule Geometries of Linear

Linear

What are the Molecule Geometries of Trigonal Planar

Trigonal Planar

Bent

What are the Molecule Geometries of Tetrahedral

Tetrahedral

Trigonal Pydramidal

Bent

What are the Molecule Geometries of Triognal Bipyramidal

Trigonal Bipyramidal

Seesaw

T-Shaped

Linear

What are the Molecule Geometries of Octahedral

Octahedral

Square Pyramidal

Square Planar

T-Shaped

Linear

What is a Wedge

Out of page toward you

What is a Dash

Into page away from you

What are Real Bond Angles compared to Ideal Bond Angles?

Bond angles that deviate from ideal are sometimes observed

Why do Real Bond Angles occur

Lone pairs take up more space and compress bond angles

What is Bond Polarity

Covalent bonds represent shared electron density between nuclei, bonds are shared equally or unequally

As electronegativity increases, what occurs to bond polarity

Bond polarity increases

What is Molecule Polarity

The sum of all bond dipoles which helps predict chemical and physical properties

How do you draw Organic Line Structures

Carbon is represented as the end of a line or the corner of a line

Hydrogen is bonded to C as C always has 4 bodns

Atoms that arent H or C are heteroatoms which must be written

What are Heteroatoms

Atoms that arent H or C in Organic Line Structures

What is the Valence Bond Theory

Electrons are in overlapping orbitals, localized between nuclei

What is Molecular Orbital Theory

Electrons are in delocalized orbits

What is Valence Theory for Hybrid Orbitals

s and p orbitals combine to produce degenerate hybrid orbitals with distinct geometries

What is the formula for Hybrid Orbitals

#Atomic Orbitals in = #Hybrid Orbital out

s + p + p + p = sp³

What works and doesnt work for Hybrid Orbitals

Works for main group, nonmetal elements, organic moleules

Doesnt work for Ionic Compounds

D Orbitals do not hybridize

How do you determine Hybridization

Count the number of Bonds (Steric Number SN), and that is the number of hybrid orbitals needed

What is a Direct Orbital Overlap

Sigma Bond

What is na Indirect Orbital Overlap

Pi Bond

Pi Bond Rotation

It takes energy for Pi Bonds to rotate

Sigma Bond Rotation

Sigma Bonds can rotate, but double bonds dont readily rotate

What does Molecular Orbital Theory help do

Provides Quantum Mechanical basis for explaining bonding, electrons are delocalized over the entire molecule. Orbitals are wave functions, so interactions are constructive or deconstructive

What are the 2 Assumptions in Molecular Orbital Theory

1. Molecular Orbitals are linear combinations of atomic orbitals: 3x+2y and -x+5y

2. Some number N atomic orbitals combine to form and equal number N molecular orbitals: 1s-1s

What is Hund’s Rule

Electrons fill subshells first before filling complete orbitals

What is the Aufbau Principle

Electrons fill orbitals in order of increasing energy levels