Sec 8.3 A
Chemical Bonding
Pg 165
A. The Electronic Nature of Chemical Bonds
1. Electrostatic Force
The force that results from the attraction or repulsion between 2 particles
Based on 4 principles
1. opposite charges attract ( protons attract electrons)
2. like charges repel ( electrons repel electrons)
3. the greater the distance between the object the less force
4. the greater the charge on the object the greater the force
2. Atomic Radius
As you move across the periodic table the atomic radius decreases
- all of the electrons that are being added are added into the same orbital at
approximately the same distance from the nucleus.
- If 1 electron is added then1 proton is added and the electrostatic forces between
the proton and electron will grow and the size of the atom will decrease.
- Protons are 2000 times larger and more powerful than electrons. So the
addition of 1 proton will greatly increase the electrostatic force in the atom.
As you move down the periodic table the atomic radius increases
- all of the electrons that are being added are added to different orbitals, so the
atomic radius will increase.
- Since the electrons are added in different orbitals, the distance between the
electrons and protons is increasing and the electrostatic force will decrease.
- If a lot of electrons are added in the same orbital, the negative charges of the
electron will start to repel each other and the atomic radius will increase.
3. Valence Electrons cont.
Open Shell – an orbital that is NOT full.
Closed Shell – on orbital that is full.
Can also be defined as:
- electrons that are able to participate in bonding
- electrons that are in OPEN shells
- combining capacity
If we ignore the transition metals
Atom
# of valence
Electrons
valence
K
1
Ca
2
Ga
3
Ge
4
As
5
Se
6
Br
7
Kr
8
1
2
3
4
3
2
1
0
Why do you think that Kr has zero?
4. Ionization Energy
-
the energy required to remove an electron from a neutral atom. The electron
removed is always on the outermost orbital.
Small atoms will have a LARGE ELECTROSTATIC FORCE and a LARGE
IONIZATION ENERGY.
Large atoms will have a SMALL ELECTROSTATIC FORCE and a SMALL
IONIZATION ENERGY.
Sec 8.3 A
Chemical Bonding
Pg 165
A. The Electronic Nature of Chemical Bonds
1. Electrostatic Force
The force that results from the attraction or repulsion between 2
particles
Based on 4 principles
1. opposite charges attract ( protons attract electrons)
2. like charges repel ( electrons repel electrons)
3. the greater the distance between the object the less force
4. the greater the charge on the object the greater the force
2. Atomic Radius
As you move across the periodic table the atomic radius decreases
- all of the electrons that are being added are added into the same
orbital at approximately the same distance from the nucleus.
- If 1 electron is added then 1 proton is added and the electrostatic
forces between the proton and electron will grow and the size of the
atom will decrease.
- Protons are 2000 times larger and more powerful than electrons. So
the addition of 1 proton will greatly increase the electrostatic force in
the atom.
As you move down the periodic table the atomic radius increases
- all of the electrons that are being added are added to different
orbitals, so the atomic radius will increase.
- Since the electrons are added in different orbitals, the distance
between the electrons and protons is increasing and the electrostatic
force will decrease.
- If a lot of electrons are added in the same orbital, the negative
charges of the electron will start to repel each other and the atomic
radius will increase.
3. Valence Electrons cont.
Open Shell – an orbital that is NOT full.
Closed Shell – an orbital that is full.
Can also be defined as:
- electrons that are able to participate in bonding
- electrons that are in OPEN shells
- combining capacity
If we ignore the transition metals
Atom
K
Ca
Ga
Ge
As
Se
Br
Kr
# of valence
Electrons
1
2
3
4
5
6
7
8
Why do you think that Kr has zero?
4. Ionization Energy
- the energy required to remove an electron from a neutral atom. The
electron removed is always on the outermost orbital.
Small atoms will have a LARGE ELECTROSTATIC FORCE and a LARGE
IONIZATION ENERGY.
Large atoms will have a SMALL ELECTROSTATIC FORCE and a SMALL
IONIZATION ENERGY.