Transcript States, Boiling Point, Melting Point, and Solubility

Phases of Matter, and
Melting/Freezing Point
Solid
Liquid
Gas
Today’s Objective
 SWBAT:
Analyze the 3 states of matter and
melting/freezing point.
Defining States of Matter
 States
of matter are NOT defined by what
they are made of.
 Example: solids can be elements (gold),
compounds (Salt = NaCl), or mixtures
(butter)
Element (Au)
Compound (NaCl)
Mixture (Milk, Salt, etc)
Defining States of Matter
 States
of matter are defined by whether they
hold SHAPE and VOLUME
Element (Au)
Compound (NaCl)
Mixture (Milk, Salt, etc)
ALL KEEP THE SAME SHAPE AND VOLUME = Solids
Defining States of Matter
– have a definite SHAPE and
VOLUME.
 Solids
Element (Au)
Compound (NaCl)
Mixture (Milk, Salt, etc)
ALL KEEP THE SAME SHAPE AND VOLUME
Particle View of a Solid
 Particles
in a solid are PACKED CLOSELY
together and they are in a FIXED POSITION.
Particles vibrate in place
Liquids
– has definite VOLUME but no
defined SHAPE
 Liquids
100 ml
Particle View of a Liquid
 Packed
CLOSELY (like a solid), but move
FREELY around each other (must stay in
contact).
Gases
 Gases
- do NOT have definite SHAPE or
VOLUME.
Bromine gas fills up the entire volume of the container
Particle view of a Gas
 Particles
can MOVE FREELY and will either
fill up or squeeze into available space.
Changes in States of Matter
 Thermal
 More
Energy – heat energy.
thermal energy = More particle
movement
Changing States
Increase Thermal Energy (Heat up)
Solid
Liquid
Decrease Thermal Energy (Cool off)
Gas
Melting Point
 The
melting point is the temperature at which a
substance changes from a solid to a liquid.
Melting point
 Melting
Point - Specific temperature
when solids turns to liquid.
 Each pure substance has a SPECIFIC
melting point.




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Examples:
M.P. of Water = 0°C (32°F)
M.P. of Nitrogen = -209.9 °C (-345.81998 °F)
M.P. of Silver = 961.93 °C (1763.474 °F)
M.P. of Carbon = 3500.0 °C (6332.0 °F)
Melting Point
 Particles
of a solid vibrate so fast that they
break free from their fixed positions.
 Occurs until of ALL the solid turns to liquid.
Increasing Thermal Energy
Solid
Liquid
Melting point
Freezing Point
 Freezing
Point – Temperature at which a
liquid turns to solid.
Freezing Point
 Freezing
Point – Specific temperature at
which liquid turns to solid.
 Generally freezing point = melting point
Freezing Point
 Particles
lose energy and begin to vibrate
very slowly.
 Occurs until ALL liquid turns to solid.
Boiling Point
and
Characteristic
Properties
Boiling Point
 The
temperature at which a liquid becomes a gas is
called the boiling point.
Boiling
– change from liquid to gas
 Vaporization happens when particles in a
liquid gain enough energy to form a gas.
 Boiling
Increasing Thermal Energy
Liquid
Boiling point
Gas
Two Kinds of Vaporization
– vaporization that takes place
only on the surface of the liquid
 Boiling – when a liquid changes to a gas
BELOW its surface as well as above.
 Evaporation
Boiling Point
 Boiling
Point – temperature at which a liquid
boils
 Each pure substance has a SPECIFIC boiling
point.

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Examples:
B.P. of Water = 100°C (212°F)
B.P. of Nitrogen = -195.79 °C (-320.42 °F)
B.P. of Silver = 2162 °C (3924 °F)
B.P. of Carbon = 4027 °C (7281 °F)
Notice temperature is constant while ice melts!
Boiling Point
and– H20
Melting Point
WATER
200
Boiling point
Temperature
150
100
Melting point
50
0
-50
-100
-150
time
Sublimation
 Sometimes
a solid can change
directly to a gas when heat
energy is added.
 This process is called
sublimation.
Characteristic Properties
 Characteristic
Property – Any property
that helps to identify what a substance is.
 Property is the same whether you have a
small sample or a large sample.
 Examples

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Density
Freezing Point
Melting Point
Boiling Point