chemistry 2ab notes
Chemistry Notes:
Metals:
• A metal consists of a lattice of positive ions surrounded by a ‘sea’ of mobile delocalised valence electrons.
• Metallic bonding is the electrostatic attraction between the delocalised electrons and the positive ions in the metallic lattice.
Properties of metals:
Property Explanation
Relatively high density The particles are very close together. This is because of high electrostatic forces between the sea of valence electrons and the positively charged nucleus.
Malleability and Ductility Because metallic bonding is non-directional-meaning that the bonds don’t have to exist with a set pair of particles, means that the positive nucleuses can easily slip over each other with bonds being broken.
Conductivity of electricity Conductivity of electricity requires two things, charged particles and they have to be freely moving. Metals have free-moving electrons, therefore they can carry a charge. Also because these electron
Conductivity of Heat In metals, not only do the atoms vibrate more when heated, but the free electrons charge around more as well. These transfer the energy much faster than just vibrations in bonds.
Heat spreads by conduction when atoms increase their vibrations, and pass this energy on to those nearby. In metals, free electrons carry the heat energy faster than the atomic vibrations and transfer it by colliding with other electrons and atoms.
High melting and boiling points Very strong electrostatic bonds between the electrons and nucleuses make it very hard for heat to overcome the bonds which make the metal solid or liquid.
Ionic Compounds:
• Ionic substances consist of positive ions and negative ions arranged in a regular lattice
• Ionic bonding is the electrostatic attraction between oppositely charged ions
Property Explanation
High melting and boiling points Strong electrostatic forces between the positive and negative ion make it hard for heat to overcome the strong bonds which are
Metals:
• A metal consists of a lattice of positive ions surrounded by a ‘sea’ of mobile delocalised valence electrons.
• Metallic bonding is the electrostatic attraction between the delocalised electrons and the positive ions in the metallic lattice.
Properties of metals:
Property Explanation
Relatively high density The particles are very close together. This is because of high electrostatic forces between the sea of valence electrons and the positively charged nucleus.
Malleability and Ductility Because metallic bonding is non-directional-meaning that the bonds don’t have to exist with a set pair of particles, means that the positive nucleuses can easily slip over each other with bonds being broken.
Conductivity of electricity Conductivity of electricity requires two things, charged particles and they have to be freely moving. Metals have free-moving electrons, therefore they can carry a charge. Also because these electron
Conductivity of Heat In metals, not only do the atoms vibrate more when heated, but the free electrons charge around more as well. These transfer the energy much faster than just vibrations in bonds.
Heat spreads by conduction when atoms increase their vibrations, and pass this energy on to those nearby. In metals, free electrons carry the heat energy faster than the atomic vibrations and transfer it by colliding with other electrons and atoms.
High melting and boiling points Very strong electrostatic bonds between the electrons and nucleuses make it very hard for heat to overcome the bonds which make the metal solid or liquid.
Ionic Compounds:
• Ionic substances consist of positive ions and negative ions arranged in a regular lattice
• Ionic bonding is the electrostatic attraction between oppositely charged ions
Property Explanation
High melting and boiling points Strong electrostatic forces between the positive and negative ion make it hard for heat to overcome the strong bonds which are