April 03, 2020, 07:41:43 PM
Forum Rules: Read This Before Posting


Topic: Types of Crystalline Solids  (Read 15770 times)

0 Members and 1 Guest are viewing this topic.

Offline Joules23

  • Regular Member
  • ***
  • Posts: 90
  • Mole Snacks: +1/-2
Types of Crystalline Solids
« on: January 11, 2008, 06:14:30 PM »
I am a bit confused ... i thought Quartz (SiO2) ...Is a Atomic-Network Solid??

I know...
There are 3 main types of crystalline solids:
Atomic, Molecular, Ionic

Within the Atomic solids, there are 3 subtypes:
Network, Metallic, Group 8A

In my assignment i am supposed to name what types of solids certain molecules or atoms are
The options i get to choose from are:
atomic
molecular
ionic
network
metallic

More than one can be selected

For diamond i put in Atomic & Network.. Correct
For Quartz i put in Atomic & Network.. Incorrect
I also tried molecular and that was incorrect

Is it possible the answer is just Network? .. I thought since network is a subtype of atomic, i must also choose atomic and network in my answer?

EDIT: or do i only chose atomic as one of the answers when there is only ONE atom at the lattice points on the structure? Such as in diamond, there is only carbon at the lattice points
« Last Edit: January 11, 2008, 07:06:37 PM by Joules23 »

Offline Alpha-Omega

  • Full Member
  • ****
  • Posts: 693
  • Mole Snacks: +360/-231
  • Gender: Female
  • Physical Inorganic Chemist
Re: Types of Crystalline Solids
« Reply #1 on: January 11, 2008, 08:18:30 PM »

Offline Alpha-Omega

  • Full Member
  • ****
  • Posts: 693
  • Mole Snacks: +360/-231
  • Gender: Female
  • Physical Inorganic Chemist
Re: Types of Crystalline Solids
« Reply #2 on: January 11, 2008, 08:39:10 PM »
Quartz:  A homogenous solid formed by a repeating, three-dimensional pattern of atoms, ions, or molecules and having fixed distances between constituent parts.


Quartz Crystal Structure:

Quartz is silicon dioxide, SiO2, consisting of one part silicon and two parts oxygen. In spite of its simple binary composition, X-ray diffraction (XRD) investigations show quartz has a complex atomic structure. This complicated structure is comprised of silicon atoms, which lie on three inrterpenetrating hexagonal lattices, with the oxygen atoms grouped in a tetrahedral manner around the silicon atoms.

The most basic structural unit of quartz, and all silicate minerals, is the (SiO4) tetrahedral configuration. In SiO2, each oxygen atom is shared with two silicon atoms; the (SiO4) tetrahedra share each of their corner oxygen atoms and form a three-dimensional network. The three interpenetrating hexagonal lattices of silicon atoms have a spiral arrangement in the vertical direction in respect to each other. This complex, vertical, helical atomic structure is manifested by various forms of twinning and by the handedness of quartz.


Offline Alpha-Omega

  • Full Member
  • ****
  • Posts: 693
  • Mole Snacks: +360/-231
  • Gender: Female
  • Physical Inorganic Chemist
Re: Types of Crystalline Solids
« Reply #3 on: January 11, 2008, 08:44:03 PM »
READ THIS VERY CAREFULLY:  http://www.chm.davidson.edu/ChemistryApplets/Crystals/NetworkSolids.html

Quartz: 

Type of Solid: Covalent Network
Intermolecular forces:  Covalent Bonding
Properties:  High Melting Point, Hard, Nonconducting
EXAMPLES:  C (diamond), SiO2 (quartz)

Sponsored Links