Types of Solids
Cards (26)
- Metallic crystals are rigid structures of metal nuclei in a wave of electrons
- Mobile electrons bond metal atoms together
- Melting points are one measure of the attractive forces since metling disrupts the crystal bonding
- Lattice energy is the energy needed to disrupt a crystal
- Mobile valence electrons explain the ability of metals to conduct electricity and heat
- Electrons carry electricity (charge) and heat (thermal energy)
- Most metals are malleable and ductile
- Alloys are solutions of solids
- Alloys are either substitutional or interstitial
- Substitutional alloys are when one metal atom takes the place of another of similar size
- Interstitial alloys are when smaller metal atoms fill in the spaces between the large metal atoms
- Substitutional alloys tend to have properties between the properties of the two metals
- Interstitial alloys are stronger and harder than the original materials
- Ionic crystals are bonded based on the attraction between cations and anions
- Large amounts of lattice energy are needed to separate ions
- An ionic crystal has a regular structure, or lattic of alternating positive and negative ions
- In an ionic crystal, hitting it with a hammer will move the atoms causing positive ions to be aligned with positive ions. the repulsive forces causes the crystal to shatter
- Molecular crystals may be composed of either atoms of the nonmetals or of covalent molecules
- Molecular crystals are held together by IMF forces
- Molecular crystals are soft with low melting points
- A network crystal has a lattice structure in which the atoms are covalently bonded to each other
- The crystal is one large molecule with a continuous network of covalent bonds
- Examples of allotropes of carbon are graphite and diamond
- Amorphous substances do not form crystals
- Amorphous substances soften gradually over a large temperature range
- Many plastics are partially crystalline and partially amorphous