Lesson 3.04
Valence Electrons
and Bonding
Vocabulary Terms
• Valence Electron- an electron of an atom, located
in the outermost shell.
• Bond – something that holds together.
• Octet Rule/Rule of Eight - chemical rule of thumb
that states that atoms tend to combine in such a
way that they each have eight electrons in their
valence shells.
• Ionic Bonding - A chemical bond that results from
electrostatic attraction between positive and
negative ions. It is due to transfer of electrons
between a metal and a nonmetal.
Vocabulary Terms
• Covalent Bonding - A chemical bond in which
electrons are shared between two atoms. The
sharing of electrons between two nonmetals.
• Electronegativity - tendency for an atom to
attract a pair of electrons that it shares with
another atom.
• Polar Covalent Bond- a covalent bond where
atoms have unequal attraction for the shared
electrons.
• Non-polar Covalent Bonds – a covalent bond in
which the atoms have an equal attraction to the
shared electrons.
Valence Electrons
• Electrons in the outermost shell or highest energy
level are called valence electrons.
Ex: Carbon – 1s2 2s2 2p2
Highest energy level is second level with four
electrons(2s2, 2p2), therefore the number of
valence electron for carbon is equal to 4.
Valence Electrons
Valence Electrons
Valence electrons = number of dots(Lewis Dot structure)
Ionic Bonding
Transfer of electron/s between a metal(+ion)
and a nonmetal(-ion)
Ionic Bonding
• Ex: NaCl
Ionic Bonding – Let’s Practice
1) Mg + Cl
2) Al + O
Covalent Bonding
Sharing of electrons between 2 nonmetals(- ion)
Covalent Bonding
Ex: CH4
Sharing of electrons between 4 atoms of Hydrogen
and 1 atom of carbon to form CH4.
Covalent Bonding- Let’s Practice
1) H + Cl
2) F + F
Polar Covalent Bond
• HF
F has a higher electronegativity than H, the atom with
greater electronegativity is able to take the electrons from
the other atom making it a negative ion and the other atom
as a positive ion. A Polar Covalent bond has an uneven
distribution of the charge, slightly negative on one end and
slightly positive on the other end.
Non Polar Covalent Bond
• H2
2 atoms of Hydrogen having the same electronegativity.
Both atoms have the same strength of attraction for the
electrons and are equally shared. A Non polar covalent
Bond have an equal attraction for the shared electrons.