Phases of Matter Notes
Lisa Peck
matter- anything that has mass, volume, and has shape
mass- the amount of matter (kg or g)
volume- the amount of space matter occupies (L or ml or cc)
density- a property of a substance, equal to its mass per volume
D= m
V
g/ml
a measure of how much mass occupies a given space
a characteristic of matter: different for each phase of the same
measure of how tightly the material is packed together
measure of how much matter is squeezed into a given space
determined by BOTH masses of atoms and the spacing between atoms
density of material can change with temperature because atoms & molecules move faster when
they are heated, and therefore usually occupy more space (V)
increase volume.......decrease density
D= m
V
density of an object does not change if the object is broken into smaller pieces
although each piece now has less mass than the original object, it has less volume too
therefore: density remains the same
solid- state of matter in wh/ atoms or molecules vibrate about a fixed position
solids are uniform, have a definite shape, and have a definite volume
solids- molecules are packed closely together
solids have fixed shape 1. amorphous - molecules are placed randomly
2. crystalline- molecules are in a repeating, geometric pattern
use an x-ray to see material’s unique crystalline pattern
liquid- the state or phase in which matter takes the shape of its container
molecules slide past each other in non-fixed positions
shape is not fixed but takes on shape of container
any material that flows and takes on the shape of its container
the atoms or molecules have enough kinetic energy (movement) to overcome the attractions
between them. The particles slide past another until the liquid takes on the shape of its container.
can change shape yet not change volume (shape determined by container)
gas- the state or phase in which molecules are far apart & move freely b/w collisions
any material that flows and takes on the shape of its container
atoms or molecules have high KE and collide & bounce apart randomly
fluid- anything that flows: (and takes shape of its container)
any liquid or gas
primary difference between liquids and gases: distance between molecules
plasma- matter consisting of positive ions (missing electrons) & free floating electrons
exists only at very high temperatures
enough Energy to break “forces” holding electrons in orbit around nucleus
The Effect Of Heat On The Phase (temp) of Water
Phases of Matter change with the addition or removal of heat energy
Atoms gain heat energy and increase movement and spacing from each other thus increasing volume.
If volume increases then density decreases.
Atoms lose heat energy and decrease movement and spacing from each other thus decreasing volume.
If volume decreases then density increases.
Generally: As Add heat energy the density decreases, as heat is removed the density increases
The melting/freezing point & boiling /condensation point for all substances never changes for that
particular substance or element. It is a physical characteristic of the substance determined by the
arrangement of the electrons (valence)
Line segments: AB, CD, and EF are distinct phases of matter (solid, liquid, & gas respectively). As
heat is added, the temperature increases. This is due to heat energy being changed into
translational KE which causes temperature to increase.
Line segments: BC (melting or freezing point) and DE (boiling or condensation point) are where
phase changes occur. As heat is added, the heat energy is turned into rotational KE, stretching or
breaking of bonds, &/or vibrational energy. Therefore, as heat is added the temperature does not
increase instead it remains a constant (thus the horizontal line). All of the heat energy goes into
breaking bonds (phase change) or is stored with in the water and does not change the temperature.