View
2
Download
0
Category
Preview:
Citation preview
Physical Science, Ch. 14 pg. 432-439,
Ch. 15 pg 462-476
Today’s Learning Objectives
1. Define Kinetic Theory.
2. How do particles move in the four states of
matter?
Matter & Thermal Energy (14-1)
Kinetic Theory - Matter is made of constantly
moving particles
Details:
1. All matter is made of tiny particles
2. They move in constant, rapid, random
motion
3. They collide
4. They lose very little energy in the collisions
Matter & Thermal Energy
Solids have particles that sit and vibrate
Liquids have particles that slide by each
other
Gases have particles that bounce
randomly
link
Matter & Thermal Energy
States of Matter –
The physical forms in which a substance can exist
The Four States of Matter –
1. Solid
2. Liquid
3. Gas
4. Plasma
Matter & Thermal Energy
Solid – the state of matter with a
definite shape and definite volume
Ex. Ice, chrome bumpers, glass
Particles vibrate in place, attracted to
each other
Class demo
Matter & Thermal Energy
Liquid – The state of matter with an
indefinite shape, but has a definite
volume
Particles move faster, less attracted to
each other
Class demo
Matter & Thermal Energy
Gas – The state with an indefinite
shape and indefinite volume
Particles move fastest, not attracted to
each other
Examples?
Class demo
Matter & Thermal Energy
Plasma – like a gas, but made up of
charged particles
99% of matter seen in universe is plasma
Examples:
Matter & Thermal Energy
Temperature: the measure of the
average kinetic energy of the particles
of a sample of matter
Today’s Learning Objectives
Describe the six state changes.
Learn the terms in this chapter.
Start boiling demo now!
Matter & Thermal Energy
Changes of state – changing from a
solid to liquid, etc.
Types:
Melting Freezing
Vaporization Condensation
Sublimation Deposition
Matter & Thermal Energy
Melting – change from a solid to a liquid
The particles are becoming less orderly (link)
Freezing – change from liquid to solid
The particles are becoming more orderly
Melting point = freezing point
Heat of Fusion – the energy required to change a substance from a solid to a liquid at melting point
Matter & Thermal Energy
Vaporization – change from a liquid to gas (link)
Could be boiling or evaporating
The particles are becoming less orderly
Condensation – change from a gas to liquid
The particles are becoming more orderly
Boiling point = Condensation Point
Heat of vaporization – the amount of energy
required for the liquid at its boiling point to become a
gas
Matter & Thermal Energy
Boiling vs. Evaporating
Boiling is vaporization throughout the entire liquid because it is all at the boiling point
Evaporation is vaporization only at the surface, this occurs below the boiling point
Matter & Thermal Energy
Sublimation – Change from a solid to gas (directly)
Particles become much less ordered
Ex: Ice on road disappearing on a very cold, sunny day w/o melting first OR dry ice
Deposition – Change from a gas to solid (directly)
Particles become much more ordered
Ex. Frost forming on window
Matter & Thermal Energy
While a substance changes state, its
temperature does not rise or fall until
the phase change is complete
See graph called
a “heating curve”
Label the Graph
line AB =
line BC =
line CD =
line DE =
line EF =
Matter & Thermal Energy
Thermal expansion: an increase in the
size of a substance when the
temperature is increased
Can also contract when cooled
Ex. – thermometers
Thermal Expansion demo(s)!
Today’s Learning Objectives
o What are the differences between pure
substances and mixtures?
o How are elements and compounds
identified?
o How are suspensions, solutions, and
colloids related?
Composition of Matter (15-1)
o What about that introductory activity
has anything to do with matter?
o Answer:
Matter has properties. These
properties can be used to identify what
type of matter it is.
Composition of Matter
o Matter – anything that has mass and
takes up space
o What are some examples of matter in this
room?
o What does NOT qualify as matter in this
room?
Composition of Matter
o Matter has two types:
1. Pure substances
2. Mixtures
o Pure substance – matter that always has exactly the same composition
o Note: your book sometimes uses the word “substance” instead of pure substance
Composition of Matter
o 2 types of pure substances
1. Elements
2. Compounds
o Element – a pure substance made up
of atoms that are all alike
o Examples?
Composition of Matter
o Elements are made of only one of the
100+ kinds of atoms
o Atom – the smallest particle of an element
oEach kind of atom has unique
properties that make it different than
the other kinds of atoms
Composition of Matter
o Compound – a substance in which the
atoms of two or more elements are
combined in a fixed proportion
Composition of Matter
o Compounds have different properties
than the elements that make them up
o Ex. sodium chloride (NaCl)
o Compounds cannot be separated into
their elements by physical means
o So you cannot filter, boil, or manually cut out
the different elements
Composition of Matter
o If matter is not a pure substance, it is a mixture
o Mixture – matter composed of 2 or more different substances that can be separated by physical means
o Examples?
o Mixtures can contain varying amounts of each substance.
o Does every cookie have the same number of chocolate chips?
Composition of Matter
o 2 kinds of mixtures
1. Heterogeneous mixtures
2. Homogeneous mixtures
o Hetero – different
o Homo – same
Composition of Matter
o Heterogeneous mixture – a mixture in
which different materials remain
separate
o Examples?
Composition of Matter
2 kinds of heterogeneous
mixtures
1. Suspension – a
heterogeneous mixture of a
liquid and solid particles that
settle out
2. Colloid – a heterogeneous
mixture with particles that
never settle out
Composition of Matter
o Homogeneous mixture – a mixture that
stays uniformly mixed and whose
particles are so small they cannot be
seen with a microscope
o Examples?
o Solution – another term for homogeneous
mixture
Composition of Matter
Today’s Learning Objectives
What are physical and chemical
properties?
Compare and contrast physical and
chemical changes.
How does the Law of Conservation of
Mass apply to chemical changes?
Properties of Matter (15-2)
o Physical property – any characteristic
of a material that you can observe
without changing the identity of a
substance
o Every substance has a specific
combination of physical properties that
make it useful for certain tasks
Properties of Matter
o Some examples of physical properties
Density
Viscosity
Freezing point
Boiling point
Conductivity
Hardness
Properties of Matter
o Important to recognize physical
changes
o Physical change – a change in size,
shape, or state of matter in which the
identity of the substance remains the
same
o Examples?
Properties of Matter
Physical changes can be used to
separate mixtures
Ex. distillation
Properties of Matter
o Chemical property – any characteristic
of a material that you can observe that
produces one or more new substances
o 2 examples of chemical properties
1. Flammability
2. Reactivity
Properties of Matter
Chemical change – when one
substance becomes another substance
2 Na + Cl2 → 2 NaCl
Properties of Matter
o Methods of recognizing chemical
changes
1. Change in color https://www.youtube.com/watch?v=BqeWpywDuiY
2. Production of gas
3. Production of energy (demo)
4. Formation of a precipitate (demo)
o Precipitate – a solid that forms
when two liquids are mixed
Properties of Matter
o These 3 methods are not perfect
ChangeChemical or
Physical change
Mix baking soda and vinegar Chemical
Water boiling Physical
Mix Kool-Aid powder in water Physical
Banana turning black Chemical
Mix milk and lemon juice Chemical
Mix melted butter and ice water
Physical
Properties of Matter
o Bottom line:
If a new substance was formed, it was a
chemical change.
Properties of Matter
Law of Conservation of Mass – the
mass of all substances before a
chemical change must equal the mass
of all substances after a chemical
change
Ex.
2 𝐻2+ 𝑂2 → 2 𝐻2𝑂
Recommended