These slides consist of information about the formation molecules by sharing of electrons between two or more non metals also known as covalent bonding. The slides describes the properties of covalent compounds.
3. Learning Objectives
• State that non-metallic elements form simple molecules
with covalent bonds between atoms.
• Describe the formation of covalent bonds in some common
compounds.
4. What is a covalent bond?
• Covalent bonds are shared pairs of electrons between non-
metal atoms.
• They are the bonds that form molecules. A molecule is two
or more atoms held together by covalent bonds.
• Some non-metal elements like hydrogen, oxygen, nitrogen
and chlorine are diatomic. They are naturally found as
molecules made from two of the same atom.
5. Covalent bonds form between non-metal atoms.
To understand covalent bonds, we
need to know the structure of the
atom.
Let's RECAP the structure of an atom
6. Electrons orbit the nucleus in
shells.
• The protons and neutrons are found in the
center of the atom in the nucleus. The electrons
are found in shells around the nucleus, and
atoms always have equal numbers of protons
and electrons.
• The shell nearest the nucleus holds only two
electrons.
• The second shell and the ones after that hold 8
electrons.
• Shells are filled starting from the first one. The
electrons in the outermost shell that are
involved in bonding are called valency electrons
7. Covalent bonds are strong.
• The nucleus of the atom contains
the protons, which makes it
positively charged.
• The electrons orbiting the
nucleus are negatively charged.
• There is a strong electrostatic
attraction between the positively
charged nuclei and the negatively
charged pair of electrons. This is
what holds the atoms together in
the covalent bond.
10. Ozone (O3) is a gas found in the Earth's atmosphere.
• Describe the bonds that hold the atoms
together and explain how you know that
the molecule has these bonds.
• When you describe a person, object,
event, or situation, you say what they are
like or what happened. When
you explain something, you give details
about it or describe it so that it can be
understood.
11. Covalent compounds
By the end of this lesson, you should be
able to:
• Describe the differences in properties
between ionic and covalent compounds.
• Explain the differences in melting point
and boiling point of ionic and covalent
compounds.
12. What is a
simple
covalent
compound?
• Non-metallic elements form simple molecules
with covalent bonds between atoms. There are many
different compounds whose atoms are held together
by covalent bonds.
• Some covalent compounds form simple
molecules, while others form giant structures. Those
compounds which form simple molecular structures
are called simple covalent compounds. We will be
focussing on these during this lesson.
• Water, carbon dioxide, ammonia, and hydrogen
chloride are all examples of simple covalent
compounds because they form small, individual
molecules.
13. Covalent bonds
are strong, intramolecular bonds.
• A covalent bond is formed when two atoms each share an electron to
make a shared pair.
• There is a strong electrostatic attraction between the positively-
charged nuclei and the negatively charged electron pair, and this force
holds the atoms together and makes covalent bonds strong.
• We call these bonds intramolecular because they are within the
molecule. So covalent compounds have strong intramolecular
bonds holding the atoms together.
