Matter or Energy? - Goochland County Public...
Transcript of Matter or Energy? - Goochland County Public...
Matter or Energy?
Everything on earth is either matter or energy
! CHEMISTRY
is the study of matter
! PHYSICS
is the study of energy and how it affects matter
Matter
Matter -- has volume (takes up space) and has mass
There are 4 forms (states) of matter
1. Solid 2. Liquid 3. Gas 4. Plasma
Matter Has Mass
! Mass is a measure of how much matter an object contains. It is measured in Grams (g).
Mass is NOT the same as Weight
! Mass does not change on different planets and is measured in grams
! Weight is mass + gravity and can change depending on the force of gravity. Weight is measured in Newtons
Who is this guy and Why was he in the news last year?
Measuring Matter in SI Units (The metric system)
! Mass – Grams
! Liquid – Liters
! Length -- meters
Matter Has Volume
Volume -- the amount of space an object takes up
Two ways to measure volume
! Volume can be measured with the equation: ! Volume = Length x Width x Height Meausre in cm.
! Volume of an object with an irregular shape is measured using a graduated cylinder and a method called displacement.
! What is the volume of your object? ! New volume – original volume = _____________
! Since we are using liquid the unit will be liters or ml not cm3.
MENISCUS
Water is adhesive
This means it adheres or
“sticks” to the sides of any
Container –
Creating a meniscus
Read the bottom line!
Volume in measured in cm3 or ml
1cm3 = 1 ml
King Henry
! King Henry Died By Drinking Chocolate Milk
Warm –up Matter
1. How many centimeters in a meter? _____
2. It makes sense to measure (SI unit) your foot using? ____
3. What does area measure?
4. How is the volume of a (regularly shaped) solid measured?
5. How is the volume of a liquid measured?
6. How many milliliters are there in a liter?
7. What does weight measure?
8. What might be the mass of an average 4th grader?
9. What does density measure?
10. What typically has the greatest density? Solid, liquid, or gas?
Why are two things the same size different Masses?
! Some substances have heavier atoms than others
! Some substances have more atoms than others
Density = Mass/Volume
! Once you know the mass and volume of an object you can easily find the density on g/ml or g/cm3
! Object: _________Object: _________
! Mass________Volume.
! D=m/v = _________________
! Object: _________
! Mass________Volume.
! D=m/v = _________________
! Mass________Volume.
! D=m/v = _________________
! Object: _________
! Mass________Volume.
! D=m/v = _________________
Do different amounts of the same material have the same density?
! YES!
Sink or Float?
The density of water is 1 g/ml
objects that are more dense than water sink
object less dense than water sink
Why does this ship float?
With all the air pockets, it is less dense than water. IF the air pockets are filled with water, what will happen?
Densities of Liquid Rubbing Alcohol .79 Lamp Oil .80 Baby Oil .83 Vegetable Oil .92 Ice Cube .92 Water 1.00 Milk 1.03 Dawn Dish Soap 1.06 Light Corn Syrup 1.33 Maple Syrup 1.37 Honey 1.42
What is the density of water?
! 1 gram/ml OR 1 gram/cm3
! Objects more dense than water will SINK
! Objects less dense than water will FLOAT
Matter is made of Atoms
Matter
! We can not see atoms with our eyes or even with a light microscope. In the 1980s, scientists created a Scanning Tunneling Microscope. Electrons tunnel between the tip and sample, creating a current that can be measured and image displayed.
Matter
! Protons have a + charge.
! Electrons have a – charge.
! Neutrons have NO charge.
! Protons and neutrons are made of smaller particles called Quarks.
Particle Theory of Matter
! “Atoms are the smallest basic units of matter.
! Atoms are always in motion.
! Atoms are the smallest particle of an element that retain the PROPERTIES of that element.
! Atoms have MASS ! Teaspoon of water has 500,000,000,000,000,000,000,000 atoms and has a mass of
5 grams. ! ATOMS combine to form COMPOUNDS
Nanotechnology is the manipulation of matter on an atomic and molecular scale
! http://go.hrw.com/activities/frameset.html?main=2333.html
How do Atoms move?
! DIFFUSION. Atoms move from a high concentration to a lower concentration until they are evenly distributed. This is called DIFFUSION.
! There is GRAVITY between objects and molecules and atoms. The farther apart they are, the less the pull of gravity. The greater the mass, the greater the gravity.
States of Matter
! Solids have a fixed volume and a fixed shape. Atoms vibrate.
! Atoms have a Strong attraction Because they are close.
Solids have different arrangements of particles that explain why some are harder or more flexible than
others
Matter
! Liquids have a fixed volume but no fixed shape
Matter
! Gases have no fixed volume and no fixed shape.
Matter
! The fourth state of matter is plasma. Plasma is a cloud of protons, neutrons and electrons where all the electrons have come loose. Plasmas are the most common state of matter. Plasma occurs naturally and makes up the stuff of our sun, the core of stars and more. On earth, plasma is naturally occurring in flames, lightning and the auroras.
Behavior of gasses
! Gasses can be compressed ! Gasses compress when
Pressure is increased. (Pressure
Goes up, volume goes down)
Hydraulic lifts are filled with gas that compresses when pressure
(a force) is applied
Charles's Law: Increasing the temperature of a gas increases its volume. Lowering the temperature of a gas, lowers its volume.
Boyle's Law: Increasing the pressure on a gas shrinks the volume of the gas. Decreasing the pressure increases the volume of a gas.
How can there be enough Helium in the tank to fill all of these balloons? Small fills 72 balloons Medium fills 144 balloons Large fills 500 balloons
Which ball has more gas? Which has higher gas pressure? Why?
Air Pressure in Layers of Atmosphere
WARM UP What happens to air density As you get higher into the atmosphere?
The density of air
Is not constant, like the density of a liquid The density of air is affected by: • pressure, • temperature • humidity. Changes in air density can modify how easily an object moves and even can cause health problems. http://images.wisegeek.com/man-looking-up-at-mt-everest.jpg
Constant
Things that are kept the same in an experiment.
Independent Variable
An independent variable is the variable you have control over. It’s what you can choose and manipulate. It is usually what you think will affect the dependent variable. Goes on the X axis
Dependent Variable (Results)
The dependent variable responds to the independent variable. It is called dependent because it "depends" on the independent variable. Goes on the Y axis
Control
Sometimes an experiment needs a basis for comparison – something you are NOT experimenting with. How would you develop a control for the plant experiment?
Quantitative data vs. Qualitative data
Qualitative – data or observations that are obtained through the five senses.
Quantitative data – data that is collected as a result of scientific measurement usually with tools like a ruler, balance, graduated cylinder, etc.
Inference vs. Observation
! Inference – a conclusion drawn from an observation
! Observation – either quantitative or qualitative. These are limited to what you can measure or gather from your senses.
Scientific Procedure
! Problem – The question the experiment will answer.
! Hypothesis – An “if/then” statement the states what you think the answer to the Problem will be. This should be done BEFORE you begin the experiment and state why you believe your hypothesis is true.
! Materials – the tools and materials that will be used in the experiment.
! Procedure – the steps to the experiment
Observations – The data collected in the experiment. This includes data that is put in charts and graphs. Also, any observations made during the experiment. Conclusion – What the outcome of the experiment was. State here whether your hypothesis was true and why or why not VARIABLES: Independent variable (IV): The part of the experiment the scientist can maniupulate or control. Dependent variable (DV): The results of the experiment. Control: A part of the experiment that is NOT being tested. A control is used as a basis for comparison. Constant: Parts of the experiment that are the same in each part of the experiment. Also called controlled variables.
HEAT!! And change of state
The speed at which atoms move is called? Kinetic Energy!
STATES OF MATTER
" Based upon particle arrangement
" Based upon energy of particles
" Based upon distance between particles
Kinetic Theory of Matter
Matter is made up of particles which are in continual random motion.
hot liquid cold liquid
Moving atoms move atoms
! Temperature is the measure of the average kinetic energy (energy of motion) atoms/molecules have.
! The transfer of this motion of atoms/molecules is called HEAT.
! This energy flows from where it is HOT to where it is NOT. Even cold things have heat energy!
ice
heat
Temperature
Temperature is the Measurement of how fast molecules are moving.
Celsius – the SI unit for temperature
0 is freezing point of water (at sea level) 100 is boiling point of water (at sea level) Do I have to know this? YES!!!
Farenheit
Freezing is 32 degrees Boiling is 212 degrees.
Kelvin Freezing point is 273 Boiling point is 373 Why these crazy numbers? Because in the Kelvin scale 0 = absolute zero. The temperature at which all matter turns solid. (freezes) and motion stops.
Do I have to memorize these numbers? NO!!!!
Converting from Celsius to Kelvin
! Add 273 degrees to the
Celsius temperature
Converting from Kelvin to Celsius • Subtract 273 degrees from
the Kelvin temperature
To get Degrees Fahrenheit, multiply the Celsius temperature x 1.8 and + 32.
Properties of Water Water coheres, which means water molecules are atrracted to each other. Why? Because one end of a water molecule has a positive charge And the other end has a negative charge so there is magnetic attraction.
Coheres – sticks to itself
Causing Surface Tension
THAT’S A FACT ---- Water is the only substance that can be found as a solid, liquid and gas at normal surface temperatures on Earth.
Change of State When a substance changes state (solid, liquid, gas) it’s identity does not change and the process can be reversed.
All three of these Pictures are of iron in different States.
Change of State: Heating matter ADD ENERGY (heating) and atoms can speed up enough to change state: Melting – solid changes to liquid.
The temperature at which this happens is the “melting point”.
Why doesn’t wood melt?
Heat of combustion is lower than the melting point. (Combustion is the temperature at which something burns).
Some things burn before they melt
Vaporization – a liquid is heated and turns to a gas
Two kinds of vaporization: 1. Evaporation occurs only at the surface of a liquid.
2. Boiling is vaporization that occurs
throughout a liquid.
**Boiling point is the temperature at which
boiling begins.
Sublimation – solid turns to a gas (no liquid phase)
Change of State (Cooling)
REMOVE ENERGY (cooling) and atoms move slower, this can cause a change of state Condensation – a gas becomes a liquid. Freezing – A liquid becomes a solid.
Cooling Curve
Heating and Cooling curves on the same graph
What Determines the State of Matter?
! Energy of the Atoms (measured as Temperature)
! Pressure on the Atoms
! Volume – The amount of space the atoms are given.
Thermal Expansion
! When an object is heated, its atoms move faster and take up more space so the size of the object expands
! Water is the exception. It gets smaller when heated and larger when frozen
Warm-up What do you think holds more heat? Which would be easier to increase or decrease the heat of? Why?
Which of these heats up Faster? Why
Rubber tire Copper Cube
Heat . . . 1. Large substances hold more heat than smaller
substances and it’s more difficult to change their heat.
2. Specific heat – The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius. What substances do you think have a high specific heat? A low specific heat?
Atom Motion is Transferred ! Classzone - Conduction, Convection, Radiation
Convection Currents
! Heat moves from where it’s hot to where it’s not
! Because hot fluids and gases are LESS dense than cold fluids and gases, they rise. ! Cold sinks ! Hot rises
Convection Currents
Earth’s Energy Budget 50% absorbed by earth’s surface 19% absorbed by the atmosphere and clouds 20% reflected by the clouds 4% reflected by the earth’s surface 6% reflected by the atomosphere
Matter Has Physical Properties ! Physical properties can be observed without
changing the substance.
! Physical changes can change some physical properties but do not change the substance.
Physical Properties A physical property is
! brittleness
! boiling point
! Color
! Density
! Ductility
! Conductivity
! Flexibility
! Hardness
! mass
! melting point
! Volume
mass melting point Volume
Physical Properties Can Change ! Physical changes can change some physical
properties but do not change the substance.
Matter’s Other Physical Properties ! Physical properties can be observed without
changing the substance.
! Physical properties that can be used to identify substances include:
! Density
! heating properties
! electric properties
! magnetic properties
Earth’s Energy Budget
Temperature and Mass Affect Motion
History of Atomic Theory
! People have been using the scientific method to study matter for centuries.
! About 2,400 years ago a Greek guy named Democritis argued that everything in the world was made of particles so small they could not be cut in half and retain the same properties.
! He called these particles “atomos” which means indivisible.
" BrainPop- Atom Theory
# John Dalton (late 1700s): Matter is made of atoms..each unique, solid spheres. They can join with other atoms to form molecules.
J.J. Thomson:
Atoms have negative particles called electrons. For every electron there is a positive particle.
Thomsons’ atom (plum pudding model)
Ernst Rutherford (1909):
Rutherford: Atoms have a central nucleus that contains protons and neutrons. Electrons exist outside in a space that is largely empty.
Niels Bohr (1913) Electrons travel in paths around the nucleus
Matter
Matter
! Today the “Electron Cloud” model is the accepted theory of the atom.
! This states that electrons do not orbit the nucleus like planets. Rather, that electrons could be anywhere in a cloud-like region around the nucleus.
Quantum Theory Video
Matter Can Be Pure or Mixed Element: Gold !"#$%&'()*+,$-",)$.+)+&)
/+&')0%&')(%1($-,*'(2)
Matter Can Be Mixed
! HOMOGENEOUS = mixed equally throughout.
! HETEROGENEOUS = not mixed equally throughout. Ex. Chex mix, salad dressing
Matter Can Be Mixed
! Mixtures can be separated by using the properties of the substances they contain.
Matter Can Be Mixed ! A solution is a mixture in which one or more solutes are dissolved in a solvent.
! A solution is a homogeneous mixture.
Ionic compound dissolved in solvent