Transcript Chemistry Lesson 10 Describing Matter

Lesson 10
Describing Matter
Standard Deviants Tape 1
IA Matter 8:26
I. Describing Matter:
a.
Matter has Mass and Volume
i.
Matter is defined as anything that has
mass and volume.
ii.
Mass
Common Pitfalls
Remember the difference
between mass and volume,
the units, and the devices
used to measure them, as
brought up in lesson 3!
1.
A measure of how difficult it is to change
the object’s state of motion.
2.
Also, it is the amount of matter in an
object.
3.
Units: grams (g), kilograms (kg), and
milligrams (mg).
4.
Mass is different from weight in several ways:
a.
Weight is a measure of the
gravitational force on an object.
b.
Mass is constant throughout the
universe – weight can change based on location.
c.
Mass is measured using a balance –
weight is measured using a scale.
ii.
Volume is the amount of space an object
occupies.
1.
Measured with a graduated cylinder
2.
Units: cubic centimeters (cm3), milliliters (mL),
Liters (L)
iv.
i.
Density is a constant ratio of mass to volume.
1.
Mass is directly proportional to volume for all pure
substances
2.
Density is equal to mass divided by volume.
3.
Units are usually g/cm3 for solids and liquids,
or g/m3 for gases.
4.
Density can be used to identify substances
– Archimedes example.
b.
Atoms are the basic units of matter
Atom – basic unit of matter
ii.
Element – a substance in which all of the
atoms are exactly the same.
Molecule – a neutral group of atoms held together by
chemical bonds. Also known as a Compound.
ii.
A molecule can contain from two to thousands of
individual atoms
II. Properties of Matter
a. Matter can be described by its properties
b. Physical properties are useful for identifying things
i.
Physical properties are properties that can be
observed or measured without changing the
composition of the matter.
ii.
Some physical properties:
1. Electrical Conductivity – the ability to carry
electricity – example: copper is a good electrical
conductor, so it is used in electrical wiring.
2. Heat Conductivity – ability to transfer energy
as
heat – example: Aluminum is a good heat
conductor, so it is used to make pots and pans.
i.
1.
Density – mass to volume ratio of a substancel measure of how tightly
matter is “packed” – example: lead is a very dense material, so it
is used to make sinkers for fishing line.
2.
Melting Point – temperature at which a solid changes state to become a
liquid – example: ice melts to liquid water at the melting point of
water.
3.
Boiling Point – temperature at which a liquids boils and changes state to
become a gas at a given pressure – example: Liquid water
becomes water vapor at the boiling point of water.
4. Index of refraction – extent to which a given material bends light
passing
through it – example: the index of refraction of water tells you
how much light slows and bends as it passes through water.
5. Malleability – ability to be hammered or beaten into thin sheets –
example:
silver is quite malleable, so it is used to make jewelry.
6.
Ductility – ability to be drawn into a thin wire – example: tantalum is a
ductile metal, so it is used to make fine dental tools.
iii.
State of matter is a physical property
1.
Solid – a state of matter with a definite
volume and shape. Atoms in solids are
held in a specific structure, but can
vibrate slightly in place.
2.
Liquid – a state of matter with a definite
volume but a variable shape. Liquids assume
the shape of their container. The atoms in a
liquid are able to slide around one another, but
stay in contact with one another.
3.
Gas – a state of matter with no definite
volume or shape. Gases expand to fill any
container they occupy. Their particles are free
to move about.
• 4 Plasma: a state of matter found in stars and
the inside of fluorescent lights, among other
places. In this state, atoms are torn apart into
smaller pieces, and these electrons and ions
move around freely. They are found in high
temperature places.
search this
imagine
• Neutron stars are compact objects that are created in the
cores of massive stars during supernova explosions. The
core of the star collapses, and crushes together every
proton with a corresponding electron turning each
electron-proton pair into a neutron. The neutrons,
however, can often stop the collapse and remain as a
neutron star.
• Neutron stars are fascinating objects because they are t
most dense objects known. They are only about 10 miles
in diameter, yet they are more massive than the Sun. On
sugar cube of neutron star material weighs about 100
million tons, which is about as much as a mountain.
• Like their less massive counterparts, white dwarfs, the
Please use the space below the three pictures to
copy the drawings from your teacher of the
three states.
Gas
Liquid
Solid
States of Matter & Changing
States Virtual Lab 2 video
c.
Chemical Properties:
ii. Chemical Properties are properties that can only
be observed when a substance reacts with another.
ii. Examples:
1. Reactivity with acid
2. Reactivity with oxygen
3. Flamability
4. A glowing splint bursts into flames
in the presence of oxygen.
5. Cobalt chloride changes from blue to
pink in the presence of water.
6. Limewater turns cloudy in the presence
of carbon dioxide.
Physical Properties Virtual Lab1
video
d.
EXTENSIVE and INTENSIVE
PROPERTIES
i.
Extensive Properites are properties which
depend on the amount of matter present.
1. Includes some physical properties, but no
chemical properties.
2. Mass, volume, length, etc are examples of
extensive properties.
3. These are things which can be measured
physically, and the measurement would change
if there was more or less of the matter present
4. For example, 10 cm3 of water weighs 10
grams. If I take away some water, it weighs
less.
ii. Intensive Properties: are properties which
do NOT depend on the amount of matter
present. They result from the way matter is
structured.
1. All chemical properties, and some
physical properties.
2. Melting & boiling points, texture, color,
density, etc.
3. Since these are based on how the
matter is put together, and not how much
your have, more or less of the matter
present doesn’t affect an intensive property.
4. For example, paper burns, regardless of
how much or how little you have.
Questions:
1. Define mass and volume, and give one
example of a proper unit for each.
2. Compare and contrast physical and
chemical properties, and give two
examples of each.
3. List the five states of matter.
4. For the three common states of matter,
draw a diagram of a container with
molecules in that state inside.
5. INTENSIVE OR EXTENSIVE?
a. Color
• Intensive
P
b. Mass
• Extensive
P
c. Flammability
• Intensive
C
d. Length
• Extensive
P
e. Density
• Intensive
P
f. Temperature
• Intensive
P
PHYSICAL OR CHEMICAL?
1.
Blue color
•
P
2.
Density
•
P
3.
Flammability
•
C
4.
Solubility
•
P
5.
Reacts with acid
•
C
6.
Supports combustion
•
C
7.
Sour taste
•
P
8.
Melting point
•
P
9.
Reacts with water to form a gas
•
C
10.
Reacts with a base to form water
•
C
11.
Hardness
•
P
12.
Boiling point
•
P
13.
Can neutralize a base
•
C
14.
Luster
•
P
15.
odor
•
P