What is bonding?
A bond is an attraction between two atoms. Bonds are formed when electrons interact with each other.
What are the types of bonds?
(and meanings)
- Ionic: complete transfer of electrons
- Covalent: electrons are shared
- Polar covalent: unequal sharing of electrons
- Non-polar: equal sharing of electrons
- Metallic: sharing electrons with no chemical reactions
What are valence electrons?
Electrons at the highest energy level (furthest away from the nucleus). Only valence electrons are used in bonding.
What is an orbital?
Space where we are most likely to find electrons. Each orbital can hold a maximum of 2 electrons.
How mant electrons can an orbital hold
a maximum of 2 electrons
What is a bonding electron?
A single electron in an orbital.
What is the octet rule?
Eight electrons in the outer shell.
What does the Aufbau principle state?
Electrons enter the orbitals of the lowest energy first.
What is the Pauli exclusion principle?
0, 1, or 2 electrons can occupy the same orbital. If two electrons are in the same orbital, they will have opposite spins.
What is Hund’s rule?
- orbitales are occupied with one electron, then doubled
- electrons in singly occupied orbitals have the same spin
What are bond pairs
- Bond pairs: Valence electrons shared as pairs
What are lone pairs
- Lone pairs: Valence electrons that are not shared
What does a Lewis diagram show?
Electrons as dots around the atomic symbol.
What is electronegativity?
The ability of one atom in a molecule to attract electrons to itself.
Who established the electronegativity scale?
Pauling established the electronegativity range from 0.7 to 4.0.
What factors affect electronegativity?
- Distance of the electron from the nucleus
- Shielding from inner electrons
- Number of protons
How does electronegativity change across the periodic table?
Electronegativity increases across a period (left to right) and up a group.
How can we determine the type of bond based on electronegativity difference?
- Ionic: difference of 1.7 - 4.0
- Polar covalent: difference of 0.3 to 1.7
- Non-polar covalent: difference of 0.0 - 0.3
What characterizes covalent bonds?
Shared electrons are attracted to the nuclei of both atoms.
What is a polar covalent bond?
Electrons are shared but not equally. The electronegativity difference is between 0.3 and 1.7.
What defines an ionic bond?
Bond between a metal and a nonmetal formed by the complete transfer of electrons.
What are the steps involved in ionic bonding?
- Loss of electron by metal
- Gain of electron by nonmetal
- Attraction between cation (+) and anion (-)
What characterizes metallic bonds?
Metal atoms are held together by their attraction to a common pool of electrons.
What are diatomic elements?
Two of the same atom forming a covalent bond, creating a stable octet.
