Transcript Standard EPS Shell Presentation

MATTER AND TEMPERATURE
Chapter Ten: Matter and
Temperature
10.1 The Nature of Matter
10.2 Temperature
10.3 The Phases of Matter
Chapter 10.1 Learning Goals
Define matter.
Identify the atom as the building
block of matter.
Explain the basis for classifying
matter as either pure substances or
mixtures.
Investigation 10A
Pure Substance or Mixture
Key Question:
 Is the matter a pure substance or is it a
mixture?
10.1 The Nature of Matter
 Matter is a term used to describe anything
that has mass and takes up space.
 Greek philosophers Democritus and
Leucippus proposed that matter is made
of tiny particles called atoms.
 Atoms were an idea that few believed.
 The first evidence was called Brownian
motion for Robert Brown, who first noticed
the jerky motion of tiny particles.
10.1 The Nature of Matter
Throwingthe
marbles
 Varying
at a tire
tube
mass
and
size
moves
the tube
of
particles
that
smoothly.
collide can have
 different
Throwing the
same marbles at a
effects.
foam cup moves
the cup in a jerky
way, like
Brownian motion.
10.1 Elements
An element is a pure
substance that cannot be
broken down into other
substance by chemical or
physical means.
All of the matter you are
ever likely to experience
is made from one or more
elements in nature.
10.1 Elements
 For example, water
can be broken down
into its elements,
hydrogen and oxygen,
when energy is added.
10.1 Atoms
A single atom is the smallest particle
that retains the chemical identity of
the element.
10.1 Atoms
Carbon atoms are different from
sodium, aluminum, or oxygen atoms.
They have different masses.
10.1 Compounds and elements
Compounds are two or more
different elements chemically
bonded together.
10.1 Examples of compounds
 Compounds
contain more
than one type
of atom
chemically
joined together.
10.1 Molecules
A molecule is a group of two or
more atoms joined together
chemically.
10.1 Mixtures
How
are
Howmany
manyatoms
molecules
inare
this
in mixture?
this mixture?
Many substances
you encounter are
a mixture of
different elements
and compounds.
10.1 Elements, compounds, and
mixtures
Can you distinguish between atoms and
molecules in these images?
10.2 Temperature
There are two common
temperature scales.
On the Fahrenheit
scale, water freezes at
32 degrees and boils at
212 degrees.
The Celsius scale
divides the interval
between the freezing
and boiling points of
water into 100 degrees.
10.2 What temperature really is
Atoms are in constant
motion, even in a solid
object.
The back-and-forth
jiggling of atoms is
caused by thermal
energy, which is a
kind of kinetic energy.
10.2 What temperature really is
Temperature measures the kinetic
energy per molecule due to random
motion.
10.2 Converting to Kelvin
The Kelvin
temperature scale
is useful in science
because it starts at
absolute zero.
To convert from
Celsius to Kelvin,
you add 273 to the
temperature in
Celsius.
10.3 Phases of Matter
 On Earth, pure
substances are
usually found as
solids, liquids, or
gases.
 These are called
phases of matter.
10.3 The phases of matter
A solid holds its
shape and does not
flow.
The molecules in a
solid vibrate in place,
but on average, don’t
move far from their
places.
10.3 The phases of matter
A liquid holds its
volume, but does
not hold its
shape—it flows.
Liquids flow
because the
molecules can
move around.
10.3 The phases of matter
A gas flows like a liquid,
but can also expand or
contract to fill a
container.
A gas does not hold its
volume.
The molecules in a gas
have enough energy to
completely break away
from each other.
10.3 The phases of matter
When they are close together,
molecules are attracted through
intermolecular forces.
10.3 The phases of matter
The forces in chemical bonds are
stronger than intermolecular
forces.
10.3 Intermolecular forces
10.3 Intermolecular forces
Within all matter, there is a constant
competition between temperature and
intermolecular forces.
When temperature wins the
competition, molecules fly apart and
you have a gas.
When intermolecular forces win the
competition, molecules clump tightly
together and you have a solid.
10.3 Melting and boiling
The melting point is the
temperature at which a substance
changes from a solid to a liquid.
10.3 Melting and boiling
The temperature at which a liquid
becomes a gas is called the boiling
point.
Notice temperature is constant while ice melts!
10.3 Melting and boiling points of
common substances
Materials have a
wide range of
melting and
boiling points.
10.3 Sublimation
Sometimes a solid
can change directly
to a gas when heat
energy is added.
This process is
called sublimation.
10.3 Plasma
In the plasma phase,
matter becomes
ionized as electrons
are broken loose from
atoms.
The Sun is made of
plasma, as is most of
the universe, including
the Orion nebula.