1.6 - 1.8 - Structure and bonding Flashcards
What are charged particles called?
Ions
What are ions?
Ions are charged particles formed when atoms lose or gain electrons. They can have either positive or negative charges
What is a positive ion called?
Cation
What are negative ions called?
Anions
Explain ionic bonding
When an ionic compound is formed electrons are transferred from a metal atom to a non-metal atom to form a positive an negative ions.
What is the definition of ionic bonding?
Ionic bonding is the electrostatic attraction between positive a negative ions
How to show ionic bonding?
Dot and cross diagram
What does a compound end in if it is has oxygen in it?
ate like sodium sulfate
What does a compound end in if it does not contain oxygen?
ide like sodium sulfide
What are giant ionic structures?
All ionic compounds form crystals that consist of lattices of positive and negative ions packed together in a regular way. A lattice is a regular array of ions . The lattice is held together by the strong electrostatic attractions between the positively and negatively charged ions
What are the physical properties of ionic substances?
Ionic substances have high melting and boiling points because of the strong electrostatic forces of attraction holding the lattice together. A lot of energy is needed to break the strong electrostatic forces of attraction between the oppositely charged ions in the giant ionic lattice. Ionic compounds tend to me crystalline this is reflected in the regular arrangements of ions in the lattice.
Explain the electrical conductivity of ionic substances
Ionic substances don’t conduct electricity when they are a solid because the ions are in a fixed position and are not free to move around and pass on the current. They do how ever conduct electricity when they are in the molten state. or dissolved in water. This happens because the ions then become free to move and pass on the current.
What is covalent bonding?
In a covalent bond a pair of electrons is shared between 2 atoms and their nuclei. What holds the atom together is the strong electrostatic attraction between the nuclei of the atoms that make up the bond and the shared pair of electrons.
How are covalent bonds often shown?
Dot and cross diagram
What are simple molecular structures?
molecules contain fixed number of atoms joined by strong covalent bonds. The forces between the molecules in a simple molecular structure are intermolecular forces. intermolecular forces between molecules are much weaker than covalent bonds. These intermolecular forces can easily broken. Simple molecular structures dont require much energy to break the intermolecular forces of attraction between the molecules. No covalent bonds are broken though because they are strong.