Lesson part 4 How can you describe matter? Matter can be describes by its physical properties, including measurements of its mass, volume, and density.
Feb 09, 2016
Lesson part 4 How can you describe matter?
Matter can be describes by its physicalproperties, including measurements of its
mass, volume, and density.
Vocabulary:MatterMassVolumeDensityStates of matterKinetic energyTemperatureHeatCondensationFreezing
Measuring Mass and Volume Matter is anything
that has mass and volume
The heaviness of something is its Mass
Weight is a measure of the force gravity puts on objects
So, this means that objects that has greater mass will have more weight.
When you step on a bathroom scale, what are you measuring?
The scale measures the effect of Earth's gravitational force on the mass of your
body.
So, how can you find the mass of your body?
You would have to compare the unknown mass of your body to some known mass.
For example, you could sit on one end of a seesaw and have someone add objects
of known mass to the other end.
M
ASS
These two boys together have the same mass as the teacher.
Grams (g) Commonly used to measure mass You can convert grams to other
measurements easily because it is part of the metric system.
Metric systemK H D – d c m
Kill Him Dead – don’t cry murder
Kilo Heto Deca (grams) deci centi milli
Move to the right or to the left the number of spots to get to the desired measure.
45.34 g = _____________Kg045.34
.04534Kg
Volume ----two ways 1. The volume of an object is the amount of
space it takes up. For example, an inflated balloon takes up more space-has greater volume- than an empty balloon.
Volume cont.2. Volume can also be used to find the
capacity- that is, how much material something can hold. Example, a pool holds more than a tea cup.
Finding Volume of solids:Prisms
V= length x width x height
V= 3cm x 3cm x 3cm V= 27cm3
Weird shapesWater
displacement method
Using a graduated cylinder:1. Look at the
bottom of the meniscus
This is 43ml .
DensityWhat is density, and how is it measured?
Imagine that you just packed two identical boxes. One box has pillows and the other books. You have forgotten which one has what.
How can you figure this out without opening the boxes you just taped up?
If you said pick them up and feel which one is
heavier, you just used density to figure this out.
Density is the amount of matter packed into a given space. In other words, density is the amount of mass in a certain volume of matter.
Just because it is bigger doesn’t mean is more dense.
Calculating density:You can calculate density if you know two things- its mass and volume.
You can find the density of the sample be diving its mass by its volume.
Formula:D= M / VDensity = mass / volume
Density = mass / volume
Example:
Find the density of a piece of metal that has a volume of 2.0 mL and a mass of 9.0 g.
D= 9.0 g / 2.0 mL D= 4.5 g/mL
Neat fact about density-Density is a characteristic of all matter.
This means that a particular kind of matter always has the same density, regardless of where the matter comes from.
Water density is 1.00 g/mL This means that a milliliter of water has a mass of 1 gram.
g/ mL)
20 degrees
Density can be used to ID matter- Suppose we find an object and measure its mass and volume to find its density.
We can use this chart to identify what it is.
Example: Mass is 85g and the volume is 100 cubic ml
What is the density?What is the mystery substance?
g/ mL20 degrees
Look here
Density and temperature Did you notice that the table of
common densities had a temperature? This is done because temperature
affects density. As a general rule, matter expands
when it is heated and contracts when its cooler.
Remember this….Temp Volume Density
Temp Volume Density
So, if it gets heated up, then the density gets smaller.
And, if it gets cooler, then the density is higher.
Sink or float? Density can be used to predict if an
object will sink or float. We know that water has a density of
1.0g/ml So, any object with a density higher
than that of water will be sure to sink.
Egg trick… A fresh egg has a density of 1.2 g/ml A rotten egg has a density of 0.9 g/ml
How will you use this information in your own life now?
Lesson part 4 review… All matter has mass and volume Mass and weight are different You can find volume by:
1. calculating it using L x W x H 2. displacement of a liquid
Density = mass / volume
Lesson part 5 What makes up matter?
All matter is made up of very tiny particles that are in constant motion
The physical state of a sample of matter (state of matter) is determined by two
things:1. how it moves 2. how the particles are attracted to each
other.
Does Matter Move?Think about a speck of dust in the light. It
looks like it is being moved around by a invisible hand.
Think about when you cook something stinky. The smell travels all over your house.
Yes… all matter is always moving!!!
How big are particles of matter?
Tiny Some are so tiny that they cannot be
seen without a very advanced microscopes.
Air is an example of matter The air in this room moves all around.
The air particles collide with everything in the room, including that particle of dust.
The collisions of air particles cause the dust to bounce around.
Do you need more evidence?
A balloon stays inflated only because the particles of air are bouncing off the
inside of the balloon.
States of matter: Gases Solid liquid
Evidence that liquid particles move around:
Watch as the food coloring is mixed into the water without stirring up
Because it mixes by itself we know that the water particles are bouncing into the food coloring, making it mover around.
What about solids?Is your desk moving?
Objects in a solid state maintain their shapes. So, solids have a definite shape that does not
change when they are moved. The particles of a solid are locked into
places. These particles have little free space. Due to
the small amount of free space, the object in a solid state is not able to be pushed together. Solids show a definite shape and a definite volume.
Forces of attraction in matter:
Forces of attraction among particles are different for different substances.
Attracting Matter:Gases: particles of gas barely touch each
other at all. These particles fly around so fast that they cannot stick together.
Liquid: particles of liquid have slightly
stronger attractions to each other. They can slip and slide past each other.
Solid: particles of solids have strong attractions. These can only vibrate back and forth in their position.
Some Characteristics of Gases, Liquids and Solids
gas liquid solidassumes the shape and volume of its
containerparticles can move past one another
assumes the shape of the part of the container which it occupies
particles can move/slide past one another
retains a fixed volume and shaperigid - particles locked into place
compressiblelots of free space between particles
not easily compressiblelittle free space between particles
not easily compressiblelittle free space between particles
flows easilyparticles can move past one another
flows easilyparticles can move/slide past one
another
does not flow easilyrigid - particles cannot move/slide
past one another
Prove It!Forms of matter
Gases
Liquid
Solid
Evidence that it moves
Inflated balloon, dust bounces around
Mixing colored water without stirring
Tough to prove…isn’t it? We need mircoscopes
Lesson 5 review
What is matter made of? Why do solids have a definite shape
but liquids and gases do not?
Lesson part 6How is the motion of particles involved in changing the state of
matter?
Important to remember:
Most matter exists in all three states- solid, liquid and gas
Another word for heat is energy.
What does energy do to matter?
Example: Water1. Water as liquid2. Ice as solid 3. Water vapor as gas
*Matter changes states when energy is added or taken away from it.
What is kinetic energy? If you throw a ball, it has energy
because it is moving.
This energy of motion is called Kinetic Energy.
Even the particles that make up matter have kinetic energy because they’re moving.
So, what determines how much kinetic energy matter will have?
Temperature
Temperature Is a measure of the average kinetic energy of the particles in a material
Many people confuse temperature and heat. This is not correct. They are related but not the same.
To remember the difference think of the bath tub and a glass of water that feels about the same to the touch. The water has the same temperature. But the bath tub contains a lot more water particles so the tub has more heat energy.
Water changes states when energy is added or taken
away Solid to liquid… melting Water to gas… evaporation Gas to liquid… condensation Liquid to solid… freezing
Evaporation As more energy is added, the liquid turns into gas.
Freezing- as more heat is removed liquid changes to solid
Lesson part 6 Review How are temperature and heat
different? What happens during condensation?