Types of bonds. Metallic Solids Ionic Solids Molecular Solids Covalent network solids. Gallium. What is a metallic bond ?. both atoms have low ionization energies and low electronegativities and will lose electrons easily (i.e. 2 metals)
The marshmallow is like the ‘delocalized electron soup’ that acts a glue that holds it together
The rice krispies are like the positive nuclei of the metal atoms that compose the solid.
* larger +ve charge across period – higher b.p/m.p.
*down group – bigger n – less attraction
*the more available e- in electron sea, the stronger the attraction (stronger bond)
Atoms are arranged in a highly ordered crystal lattice structure which maximizes the attractive forces between oppositely charged ions and minimizes the repulsion between like charged ions (the crystal structures are determined experimentally using X-ray crystallography).
No, you don’t need to know these! They’re just neat lookin’
Generally strong bonds - very high melting and boiling points, solids at room temperature, not soluble in polar or nonpolar solvents and they do not conduct electricity.
Can be soft (2-d networks like graphite) or hard (3-d networks like diamonds) or fibres (1-d networks like asbestos)
Allotropes: elements that exist in different physical forms with different physical properties but the same chemical properties.
For example graphite and diamond are allotropes of carbon (as is “Buckey ball”). Both form carbon dioxide and water when undergoing combustion but only graphite conducts electricity and diamond is one of the hardest substances known.