NOTES (kap. 1,2) Flashcards
Atoms, molecules and ions may be found as gas (g), liquid (l) or solids (s).
Describe each matter?
(gas) = state of matter which completely fills the container that it occupies.
(liquid) = Takes the shape of the container that it fills and exhibits a well defined surface boundary seperating the liquid from the unoccupied part of the container.
(solid) = matter that maintains a certain shape independent of the shape of the container.
What is the key difference between the states of matter?
It relates to the ability of the particles to move relating to each other.
(gas) = the particles of a gas are far apart in constant and disordered motion, travelling long distance compared to particle diameter before colliding to another particle or wall. (interactions between particles are limited)
(liquid) = Particles are in continuous motion, but always in contact with other particles restricting their motion. (traveling only fraction of diameter before colliding with another particle).
(solid) = Particles are in close contact, and unable to move away from the ordered array in which they sit oscillating around an average position.
Solids are further classified according to the order of molecular packing. Which are they?
1) Crystalline solids: characterized by short range and long range leading to a regular structure extending through the crystal.
Crystaline solids may be further divided into:
- polymorphs
- hydrates
- solvates
- co-crystals.
2) Amorphous solids: characterized by lacking the long range regular structure. It may be approximated with a supercooled liquid (In short: Amorphous solids act somewhat like liquids that have been cooled down but didn’t fully become a crystal!).
Can some molecules be found in a fourth state?
Yes.
1) Mesophase/liquid and crystalline phase (between the liquid and the crystalline phase).
2) Condensed states (between the liquid and solid states, and are incompressible (cannot be reduced in volume)).
3) Fluid states (between the gas and liquid states, and they form when subjected to external forces such as gravity).
