Structure And Bonding Flashcards
What is ionic bonding?
Ionic bonding is when metals lose electrons to become positively charged ions and non metals gain electrons to become negatively charged ions. These oppositely charged ions are attracted, forming an ionic bond.
Ionic bonding has SEABOCI:
Strong Electrostatic Attractions Between Oppositely Charged Ions
What is covalent bonding?
Covalent bonding is when non metal atoms bond together by sharing pairs of electrons to make covalent bonds.
The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces, making covalent bonds very strong.
What is the structure and bonding of a simple molecular substance?
Simple molecular substances are made up of molecules containing a few atoms joined together by covalent bonds.
They have low melting and boiling points due to the weak intermolecular forces holding the substance together. These intermolecular forces require very little energy to be overcome.
They do not conduct electricity - no free electrons
Giant covalent structures and allotropes of carbon
Giant covalent structures contain many strong covalent bonds which require a lot of energy to be broken. This gives them very high melting and boiling points.
They don’t contain charged particles, so they don’t conduct electricity. Except graphite and graphene.
Allotropes of carbon such as diamond, graphite, graphene, and fullerenes are all giant covalent structures.
What are polymers?
In a polymer, lots of small units are linked together to form a long molecule that has repeating units. All the atoms in a polymer are joined by strong covalent bonds.
The intermolecular forces between polymer molecules are larger than between simple covalent molecules, so more energy is needed to break them. This means most polymers are solid at room temperature.
What is metallic bonding?
Metallic bonding contains strong electrostatic attractions between a sea of delocalised electrons and positively charged ions. These forces of attraction hold the atoms together in a regular structure and are known as metallic bonding. Metallic bonding is very strong, giving metals high melting and boiling points.
The delocalised electrons carry electrical current through the whole structure, so metals are good electrical conductors.
The layers of atoms in a metal can slide over each other, making metals malleable.
