KING FAHD UNIVERSITY OF
PETROLEUM AND MINERALS
PYP 001
Fall 2012 (Term 121)
Chapter 4
States of Matter
4.1: Solids
• Matter exists in different states and can change
from one state to another when it gains or releases
energy.
• Solids, liquids, and gases are three states of
matter. A state of matter is the physical form in
which a substance exists.
• There is a fourth state of matter known as plasma.
• plasma is less abundant on Earth than solids,
liquids, and gases are.
• 99 percent of the known matter in the universe is in
the plasma state.
4.1: Solids
• Matter exists in the plasma state only at extremely
high temperatures
• Plasma is found naturally in lightning bolts,
auroras, and stars.
• It is created artificially in fluorescent bulbs and
neon lights.
4.1: Solids
Characteristics of a Solid:
• Matter is made up of small particles. Theses
particles are in constant motion. As they move,
they attract, or pull, other particles toward
themselves. The state of matter is determined by
how fast the particles move and how strongly they
are attracted to one another.
• Matter in the solid state has defined volume and
shape.
• A solid maintains its volume and shape because
the particles in it are packed tightly in relatively
fixed position. They move but they only vibrate
about fixed points. Fig. 4.2
4.1: Solids
• Why do the particles
in a solid stay close
together?
• Einstein used Bose’s discovery to predict the
existence of a fifth state of matter. It is a dense
collection of atom parts called bosons, and it exists
at extremely low temperature. It’s existence was
finally proven in experiment in 1995.
4.1: Solids
Types of Solids:
• Solids can be classified as crystalline solid or
amorphous according to the arrangement of their
particles.
• Crystalline Solids: the particles are arranged in a
repeating patterns of rows. ( Salt, sugar, sand , ice
, quartz…)
• Amorphous solids: The particles are found in a
random arrangement ( rubber, glass, wax…)
• Fig. 4.3
4.1: Solids
4.2: Liquids:
Characteristics of liquids:
• Matter in the liquid state has a definite volume, but
not a definite shape. This means that the amount
of liquid in a sample stays the same.
• A liquid takes the shape of its container.
• The particles in a liquid move more rapidly than do
those in a solid (liquid flow). Fig. 4.5
4.2: Liquids:
Surface Tension: ( raindrops)
• The particles below the surface of a liquid are pulled
up only toward the sides, and toward the center.
• The surface particles are pulled only toward the
center and the sides. Ex. See Fig. 4.6
Viscosity:
• A liquid’s resistance to flow.
• Honey flow more slowly than water because it has a
higher viscosity than water.
• A liquid’s viscosity depends on the attractions
between its particles.
• Strong attraction less flow more viscous
Summary:
• 4.1: Solids:
• Matter can exist as a solid, liquid, gas, and as plasma.
• A solid is matter with a definite shape and a definite
volume.
• The particles in a crystalline solid are arranged in an
organized pattern of repeating rows, whereas the
particles in an amorphous solid are not arranged in an
organized pattern.
• 4.2: Liquids
• A liquid has a definite volume, but not a definite shape.
• Uneven forces on the surface particles of a liquid result in
surface tension.
• A liquid’s resistance to flow is its viscosity.
4.3:Gases
• A gas is matter that does not have a definite volume
or a definite shape. The particles in a gas move
rapidly in all directions.-its particles are at great
distances
• Because they are moving so quikly, gas particles
overcome the attractive forces between them.
• As far apart as possible the gas expand to fill its
container.
• It takes on the volume and shape of the container.
• Diffusion: The spreading of gas particles throughout
a given volume until they become uniformly
distributed.
4.3:Gases
• 4-7
• 4-8
4.3:Gases
Gas Pressure
• The pressure of gas is the force exerted on surface
divided by the total area over which the force is
exerted. The SI unit used to measure pressure is
Pascal(Pa)=N/m2.
• 1 Kilopascal=1000 Pascal.
4.3:Gases
Boyle’s low
• A gas is compressed when its particles are
squeezed together.
• In the mid -1600s, the British scientist Boyle
recognized that the pressure and the volume of a
gas are inversely related. (when one value goes up,
the other goes down).
Boyle’s low: States that for a fixed amount of gas at a
constant temperature, the volume of the gas
increases as its pressure decreases.
• Did you know
• Fig 4.10
4.3:Gases
Charles’s low:
• Charles’s low states that for a fixed amount of gas,
the volume of the gas increases as its temperature
increases. (volume and temperature are directly
related).
• Fig 4.11
4.4: changes of state:
• A change of state is the conversion of a substance
from one physical form to anther.
• The composition of a substance does not change
as the substance is converted from one state to
another.
Energy
• All changes of state involve a change in energy.
•
Energy is ability to do work or cause change.
• The more kinetic energy a particle has, the faster
and farther it moves.
• The total kinetic energy of all the particles in a
sample is known as thermal energy.
4.4: changes of state:
• When matter changes from one state to another,
thermal energy is absorbed or released.
• Thermal energy is that is transferred form one
substance to another is called heat.
• When matter is heated, it gains thermal energy.
Matter releases thermal energy as it cools.
• The average kinetic energy of all the particles is the
sample’s temperature.
• Fig 4.12
4.4: changes of state:
Melting
• The change from the solid state to the liquid state is
called melting.
• The temperature at which substance changes from
a solid to a liquid is the substance’s melting point.
(0o C for water, 801o C for salt).
• Unlike crystalline solids, amorphous solids do not
have definite temperature at which they melt.
Freezing
• When a liquid is cooled, it loses thermal energy.
4.4: changes of state:
Freezing
• The change of state from a liquid to a solid is called
freezing.
• The temperature at which a substance freezes is
the freezing point.
• Freezing is the reverse of melting.
Vaporization
• The change of state from a liquid to a gas is called
vaporization.
• Ex: Perspiring cools a person because liquid
perspiration removes thermal energy from the body
as it changes into a gas. There are two different
forms of vaporization: boiling and evaporation.
4.4: changes of state:
•
vaporization that occurs throughout a liquid is
called boiling.
• The temperature at which a substance boils is
called the substance’s boiling point. (for water is
100oC – at sea level).
• Atmospheric pressure is lower at higher elevations
than it is at seal level. Denver, Colorado, is 1.6Km
above sea level. The boiling point of water there is
about 95oC.
Evaporation: is vaporization that occurs at the surface
of a liquid and at temperatures below the boiling point
of a substance.
4.4: changes of state:
• Condensation: the change of state from a gas to a
liquid is called condensation (condensation occurs
when a gas cools).
• The condensation point of a substance is the
temperature at which a gas condenses.
Condensation is the reverse of boiling. Therefore,
the condensation point is the same as the boiling
point at given pressure.
Sublimation
• The change of state in which a solid changes
directly to a gas.
• During sublimation, the particles of a solid absorb
enough energy so that they change from being very
tightly packed to being very spread apart.
4.4: changes of state:
Analyzing heating curve
• A process that absorbs energy is called an
endothermic process. Ex: melting, vaporization and
sublimation.
• A process in which energy is given off or removed
from a substance is called an exothermic process.
Ex: freezing and condensation.
• Fig 4.19
Summary:
• 4.3: Gases
• A gas has neither a definite volume nor a definite
shape.
• Boyle’s law states that the pressure and volume of a
gas are inversely related at a constant temperature.
• Charles’s law states that the volume of a gas is
directly related to its temperature.
• 4.4: changes of state
• A change of state is a physical change in which
matter changes from one state to another without
changing its identity.
Summary:
• Every change of state involves either the release or
the absorption of energy.
• Melting,
vaporization,
and
sublimation
endothermic changes of state. Freezing
condensation are exothermic changes of state.
are
and
• A heating curve shows the relationship between
energy and temperature as a substance changes
from one state to another.