Chapter 3 - Bonding Flashcards
What are negative ions called?
Anions
What is an ionic bond?
The electrostatic atteaction between oppositely charged ions
Why do ionic compounds have a high melting/boiling point?
The energy required to melt an ionic solid is large due to the large number of strong electrostatic attractions between the positive and negative ions.
Why are ionic compounds usually soluble in water?
Water likes charged substances and likes to surround the ions that have broken out of the lattice. When the moving water molecules hit the ionic lattice they can knock off ions and water molecules surround the ions
Why do ionic compounds conduct electricity when molten or whenin aqueous solution?
In a liquid or aqueous state, ions are free to move and carry charge
What is a covalent bond?
A covalent bond consists of one or more shared pairs of electrons between two atoms
What are positive ions called?
Cations
What are covalent bonds found in?
- Molecular elements and compounds (e.g. Cl2, P4, CO2)
- macromolecular covalent elements (e.g. Graphite, diamond)
- molecular ions (NH4+ , NO3-)
What is a coordinate bond?
A coordinate bond contains a shared pair of electrons with both electrons supplied by one atom
What is a metallic bond?
A metallic bond is the electrostatic attraction between the delocalised electrons amd the positive metal ions in the lattice
What are the properties of ionic compounds?
High melting points
Soluble in water
Conduct electricity in water
What are the properties of metals?
- Metals conduct electricity
- Metals conduct heat
- Metals are ductile and malleable
- Metals have high densities
- Most metals have high melting points
Explain why metals conduct electricity
There are delocalised electrons in the metal structure and these electrons can move. An electric current flows because of the movement of electrons or charged particles. These delocalised electrons can carry the charge.
Explain why metals conduct heat
The delocalised electrons in the metal structure enable heat energy to be passed through the metal
Explain why metals are ductile and malleable
Metals have a layered structure, these layers can slide over eachother without disrupting the bonding