2006-06-06 16:40:16 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
In my years of teaching, it seems that everything in chemistry is related to stability. The network solids are very stable structures and form strong bonds.
A melting point in chemical terms is when the physical property of heat is capable of changing the configuration of the bonds. This configuration will be resistant to change if it is in a stable state, because the change to the liquid form is an increase in entropy (chaos). Therefore a high temperature would be required to change the form.
2006-06-06 17:51:54 · answer #1 · answered by weilder 4 · 0⤊ 0⤋
Network Solids
2016-10-29 21:49:23 · answer #2 · answered by ? 4 · 0⤊ 0⤋
There is a lattice energy associated with forming such long range order. Its the energy required to transform a crystal lattice to gaseous elements. As it was said above, these lattices have are highly stable due to two major bonding components, electrostatic attraction and repulsion (due to electron cloud overlap since the atoms tend to be very close together). An optimal geometry and internuclear spacing between lattice elements is found which is of course the most stable configuration based on the ultimate balance between attraction and repulsion. In order to break the lattice a significant amount of energy is required to take a molecule (or atom) out of the lattice by moving it away (attraction from others in the lattice begins to dominate). The geometry and configuration of items in a lattice are all dependent on eachother, and even a small defect in this lattice (missing molecule) can severely lower the stability of the lattice making it easier to mobilize a component. Its like a well built truss structure of a building roof...every component is required for the strength and even a few missing or incorrectly built pieces can have a huge weakening effect on the whole structure.
2006-06-07 17:37:16 · answer #3 · answered by Robert L. D 2 · 0⤊ 0⤋
The atoms or molecules that comprise the solid are packed close together that why they have high melting points.
2006-06-06 19:08:45 · answer #4 · answered by Anonymous · 0⤊ 0⤋
For the same reason that the strongest scaffolding consists of joints linked to their neighbours by 4 pipes pointing away from each other at angles of 109.5 degrees. The only reason we don't make scaffolding like this is because you wouldn't have any horizontal walkways. Diamond, tungsten carbide and boron nitride all have this structure.
2006-06-06 18:31:46 · answer #5 · answered by zee_prime 6 · 0⤊ 0⤋
Molecules in these solids are strongly bound by covalent bonds and melting would break many of these bonds.
2006-06-06 18:51:26 · answer #6 · answered by RAWK_HAWK 2 · 0⤊ 0⤋
becus they need to be more resistant to heat
2006-06-06 16:46:51 · answer #7 · answered by Anonymous · 0⤊ 0⤋