Covalent bonds form when electrons are shared between two elements that have close electronegativity, so neither element takes or loses electrons. Ionic bonds form when a metal takes electrons from a nonmetal, giving the metal a positive charge and the nonmetal a negative charge so they are attracted. Covalent bonds form between nonmetals and have low melting points, while ionic bonds form between metals and nonmetals and have high melting points due to the strong electrostatic forces between the ions.

1. Covalent and Ionic Bonding
By: Joe Chandler

2. Covalent Bonds
 Covalent bonds are formed when
electrons are shared between two
elements. The elements in covalent
bonds are often close in
electronegativity. This is because if
one was much higher than the other it
would steal an electron not share it.
Neither takes electrons or loses any.
Form molecules. Close
electronegativity.

3. Ionic Bonds
 In ionic bonds are when metals take
electrons fro nonmetals. When the
electrons are stolen one becomes
negative and one becomes positive so
they are attracted towards each other.
This forms a crystal structure because
the negatives will always be surrounded
on all sides by positives and not touch
other negatives so they become a 3-d
structure. The one that is taking is a
higher electronegativity because it
attracts the electrons from the other
element with a lower pull. Very different
electronegativity.

4. Compare and Contrast
 In order for the covalent bonds to form the
electronegativities need to be different
because that way the electrons can be
shared not stolen and ionic need to take so
the higher electronegativity allows that to
happen. Covalent are nonmetal to nonmetal
and ionic are metal to nonmetal because of
electronegativities. Ionic has high melting
and boiling points because bonds need to
break but covalent are low because bonds
don’t need to. Covalent are flexible o bond
needs to break ionic are hard because bonds
are strong.

5. Examples
 Ionic  Covalent
 Sodium Iodide  Methane
 Calcium Chloride  Water
 Potassium Iodide  Ammonia
 Sodium Fluoride  Carbon Dioxide

6. Comparison
 Water  Sodium Fluorine
 Water is covalent  It is ionic because
because both sodium has a low
oxygen and electronegativity and
hydrogen are fluorine has the
nonmetals with close highest
electronegativities. electronegativity of
They don’t take the any element.
electrons from each Fluorine takes
other they share. electrons and one
becomes positive
and one negative so
they are attracted to
each other.

7. The End