Bonding Flashcards
The 3 types of strong chemical bond
- Ionic
- Covalent
- Metallic
What do ionic bonds form between?
a metal and a non-metal
What do covalent bonds form between?
non-metal elements
What do metallic bonds form between?
metallic elements
Metallic bonding
Metallic bonding is the strong electrostatic attraction of positive metal ions surrounded by a sea of delocalised electrons.
Conductivity of metals
All metals are good electrical and thermal conductors. They are good conductors of heat because the delocalised electrons help transfer energy through the metal very efficiently. The delocalised electrons can also flow and hence metals can also conduct electricity very well.
Strength of metals
The majority of metals are very strong as there is a strong electrostatic attraction between the positive metal ions and delocalised electrons. The strength of the metallic bonding depends on the balance between the charge on the metal ions, the size of the metal ions and the number of electrons in the sea of delocalised electrons. The strongest metals have ions which are small, have a large positive charge, and many delocalised electrons.
Malleable and Ductile Metals
Metals can be hammered into shape (are malleable) and can be pulled into wires (are ductile) because rows of metal ions can slide past one another. If the ion lattice changes shape the delocalised electrons will still move with the ions to continue holding them together.
Melting and Boiling Points of Metals
This is directly linked to the strength of the metallic bonds. The stronger they are, the higher the melting point and boiling point will be.
Ionic Bond
An ionic bond is the strong electrostatic attraction between oppositely charged ions.
Covalent Bond
A covalent bond is a shared pair of electrons between two atoms.
Coordinate Bond
A coordinate bond is a shared electron pair which have both come from the same atom
How many bond pairs and/or lone pairs are in a molecule with a square planar shape?
2 lone pairs and 4 bond pairs
What is something that is always true of inorganic ionic compounds?
they form giant structures
What is the bonding of silicon dioxide?
- Each silicon atom bonds with four oxygen atoms so each silicon atom forms four single covalent bonds
- It is an example of a giant covalent structure
How to tell if a molecule will have permanent dipole forces?
it has high difference in electronegativity between its atoms but if it is spread evenly then the dipole cancels out
Does graphite contain delocalised electrons?
Yes
What molecules form hydrogen bonds?
any molecule that has a hydrogen atom directly attached to an oxygen or nitrogen
Does ammonium chloride contain a coordinate bond?
Yes
What drawing the shape of an ion, what must you remember to add?
Square brackets around the shape and the charge of the ion