03 - atoms & bonding

Atomic ionization

Number of electrons can change

• ions form by addition or subtraction

ex: sodium can give electron atom away

Where are the elctrons?

Wave mechanical:

• electron found somewhere in a volume of space

• a lot of energy (moving around everywhere)

What are the laws for electrons to find homes?

• low energy (close to energy)

• repel each other (they are spaced)

• occupy distinct bands (must fill all of each energy level (7 total))

• Not much room close to nucleus (2,8,8,8,8…)

orbitals

SUBDIVISION

• within energy levels

• volumes where electrons hag out

• higher energy levels == more orbitals

• 4 kinds of orbitals

What are the 4 types of orbitals?

1. S-orbital

2. P-orbital

3. D-orbital

4. F-orbital

How many orbitals in S sublevel?

1

How many orbitals in P sublevel?

3

How many orbitals in D sublevel?

5

How many orbitals in F sublevel?

7

Ground State:

Electrons are gonna fill the lowest energy state

Electrons in lowest energy configuration

Valence electrons

Outermost shell of electrons

# of s,p,d,f

1. S=2

2. P=6

3. D=10

4. F=14

Electronegativity

The relative electron attracting power of an atom

Electronegativity in periodic table

Increases going upwards and right

families (left to right)

alkali metals

alkali earth metals

halogens

noble gases

Bonding types

1. Ionic

2. Covalent

3. Metallic

ionic bond

metal / nonmetals

• electrons transferred

covalent bonds

non metal/ non metal

• electrons shared

metallic bonds

metal / metal

• electrons shared

Mixed Character Ionic/Covalent Bonds

• Calculate the % of Covalent & Ionic

• Mainly Ionic or Covalent, will have HIGHER TM

strength of bonding types

1. ionic

2. covalent

3. metallic

4. van der waals

What are the 3 types of Secondary Bonding (Van der Waals)

1. Fluctuating Induced Dipole Bonds (random)

2. dipole-dipole

3. Polar Molecule-Induced Dipole Bonds (induced-dipole)

Fluctuating Induced Dipole Bonds (random)

• Random Electrons distribution fluctuation

• Short-lived induced dipole

• Weak, short-lived bond

ex: n2 + n2

Polar Molecule-Induced Dipole Bonds (Induced-dipole)

• Unbalanced electronegativities

• Molecule is polar (dipole)

• Induces dipole in neighbor

• Bond

ex: h2o + o2

dipole-dipole

two polar molecules

• ex: h2o & h2o

hydrogen bonding

hydrogen with N, F, O

% Ionic character problem:

What electronegativity will give you 50% IC?

X = 1.67