Free e - move rapidly in response to electric fields, thus metals are excellent conductors of electricity.

Free e - transmit kinetic energy rapidly, thus metals are excellent conductors of heat.

However, individual atoms are held loosely to other atoms, so atoms slip easily past one another, so metals are ductile.

Covalent bonds form between non-metal atoms Covalent bonds involve sharing a pair of electrons, each atom thinking it has a complete outer shell because of the shared electrons +

Molecular compounds generally have low melting and boiling points. Molecular compounds are usually gases or liquids at room temperature. Molecular compounds do not conduct electricity when dissolved in water.

As a metal and a non-metal approach one another, the valence electrons interact and the metal (indicated by the red sphere) transfers its valence electrons to the non-metal (indicated by the blue sphere). The metal becomes positively charged (through the loss of electrons) and the non- metal becomes negatively charged (through the gain of electrons). In this way, both the metal and the non-metal complete their valence shell to obtain a stable electron configuration

Ionic bonds form between metals and non-metals + Cl Ionic compounds consist of a regular three dimensional pattern of alternating positive and negative ions producing an electrically neutral compound.

Ionic compound conduct electricity when dissolved in water or when molten. Ionic compounds are solids at room temperature. Ionic compound have high boiling and melting points.

Ionic compounds are brittle

 very hard substances very high melting points small number of substances in this category ie: diamond C (s) graphite SiC (s) quartz SiO 2(s)

 electrons are transferred from metal to non-metal (this creates a very polar molecule)  ions arrange themselves so they are near the opposite charge  this forms an ionic crystal lattice

Section 3.5 Questions  P.129 # 1 – 11