Substances
materials, where the internal properties are in focus of interes, e.g. the involved atoms and the kind of their arrangement
Bodies
Contrast to substances
characterized by a special form, shape or magnitude (external properties)
characterized by a special form, shape or magnitude (external properties)
Pure Substances
have a defined composition and under a given pressure constant melting- and boilingpoints
cannot be seperated into other kinds of matter by any physical process
cannot be seperated into other kinds of matter by any physical process
Mixtures
several substances in variable positions
can be seperated into two or more substances by physical means
can be seperated into two or more substances by physical means
Homogenous Substances
are of uniform composition down to the areas of atomic magnitude
at every point the same composition (molecules)
at every point the same composition (molecules)
Heterogenous Substances
a non-uniform mixture of physically distinct parts, each with different properties (>phases)
(mixed) Phases
one of several different homogenous materials present in the portion of matter under study
the distinguished parts/areas of existence may be gaseous, liquid or solid
(phase 1 water/phase border/ phase 2 oil)
the distinguished parts/areas of existence may be gaseous, liquid or solid
(phase 1 water/phase border/ phase 2 oil)
state of matter (phase): | existence of matter in...
solid state: stable form, defined volume
liquid state: instable form, defined volume
gaseous state: instable form, undefined volume
liquid state: instable form, defined volume
gaseous state: instable form, undefined volume
Phase transition:
solid > liquid: melting
solid > gaseous: sublimation
liquid > gaseous: boiling
liquid > solid: freezing
gaseous > liquid: condensation
gaseous > solid: resublimation
solid > gaseous: sublimation
liquid > gaseous: boiling
liquid > solid: freezing
gaseous > liquid: condensation
gaseous > solid: resublimation
(Chemical) Elements:
- basic materials, cannot be decomposed by any chemical reaction into simpler substances (but by physical methods)
- a type of matter composed by only one kind of atom, each atom of of a given kind having the same properties
- modern definition: elements are substances whose atoms all have the same atomic number
- 118 elements known, 85 natural occuring, 33 artificial
- a type of matter composed by only one kind of atom, each atom of of a given kind having the same properties
- modern definition: elements are substances whose atoms all have the same atomic number
- 118 elements known, 85 natural occuring, 33 artificial