Do Now:-Copy HW and take out Saving FredMonday: Finish LabTuesday: Measurement Practice DittoWednesday: NO HW Thursday: Metric Unit PracticeFriday: NO HW

Do Now: Focused Free WriteDirections: On a clean sheet of loose-

leaf paper in your class-work section, answer the following questions in complete sentences

1)Why are goals important to success?2)What are some of your goals for this

year in Science?

Do Now: Focused free Write

Directions: Take a packet from the Do NOW desk. On a clean sheet of loose-leaf paper in your class-work section make 5 observations about our classroom…

Unit 1: IntroductionThe Nature of Science

When it comes to looking at life, I always tend to round up, but in Science I know to

simply follow the rounding procedure! P.S. My name is Elle

1.Observations:• Are the use of the 5 senses to learn

something about the environment.

a. When you observe, you use your ____________ to take in everything that is happening around you, paying close attention to detail

b. Examples:• The rock is round and smooth.

Senses

2.INFERENCE:-Are interpretations of your

observations.-In other words, when you infer

you form a conclusion based on something you observed.

i. The round and smooth rocks must have been carried here by running water.

b. An example of an inference is:

ii. Since the dog is wagging his tail he must be happy.

iii. Make an inference about something your observe in the classroom.

b. Examples

Prediction• Lets looks at this picture again, what

will eventually happen to the circled rock?

How is a prediction different than an inference?

3.Prediction• An educated guess as to what will

happen in the near future based usually on your observations and inferences.

• An example of a prediction: i. An angular rock will eventually

become rounded if it stays in the stream.

ii. Ms. Gill will wear something stylish tomorrow.

Closure• Write a paragraph in your own words

comparing and contrasting the three terms: Observation, Inference and Prediction in your note packet

Do Now• Observation/ Inference Worksheet on

the Do NOW desk• Take out homework

The Nature of Science• Working science does not simply follow a

stepwise procedure such as the scientific method but rather limits, a level of uncertainty, biases, reasons for its reliability and social aspects to consider.

• Understanding of our world are constantly evolving. There is much more to science than simply following the scientific method, a stepwise formula to solve problems by testing proposed solutions.

The Nature of Science• The World Is Understandable• Scientific Knowledge Is Durable• Scientific knowledge is inherently uncertain.• Scientific Ideas Are Subject To Change• Science Demands Evidence• Science Is a Blend of Logic and Imagination• Science Explains and Predicts• Science Is Not Authoritarian• Scientists Try to Identify and Avoid Bias• There Are Generally Accepted Ethical Principles in the

Conduct of Science• Science Cannot Provide Complete Answers to All Questions• Science Is a Complex Social Activity• Scientists Participate in Public Affairs Both as Specialists

and as Citizens

Lets read the blurb in your Note packet

together!

Carolina Bay Formations

Carolina Bay Formations

Scientific Theory• An idea explaining scientific

phenomenon supported by evidence gathered from repeated experiments

Lets read the blurb in your Notepacket

together!

Hypothesis• A testable statement that describes

the solution of an experiment. Written as “If_____________, then _______________ because _______________.

Lets read the blurb in your Notepacket

together!

Scientific Method• a stepwise formula to solve a

problem by testing a Hypothesis, it is often used in the classroom but not always in true science.

Do Now: Scientific Method Worksheet on “Do Now”

DeskCopy this Weeks Homework:

Monday: Scientific Method HW ditto & Finish Skittles Lab

Tuesday: Doing Science WorksheetWednesday: Finish “Saving Fred” Lab

Thursday: Graphing WorksheetFriday: NO HOMEWORK… Enjoy your three

day weekend!

Scientific Method:• Steps that scientist use to solve a

problem!

Scientific Method:1.State the problem!Example: I observe two plants

growing in my house. Why is one taller than the other?

Scientific Method:• 2. Gather information.

(Research!)observations, research, brainstormingExamples:1. Are both plants the same species? 2. Are both plants the same age?3. Are both plants receiving the same resources to survive?

Scientific Method3. Develop a Hypothesis.-based on observations and research-Statement, NOT a question!-can be tested• Write your hypothesis in the space

provided!

Scientific Method3. Develop a Hypothesis.Ex:

If I deprive a plant of natural sunlight then it will die because plants need sunlight to survive.

Scientific Method:4. Test you HypothesisPlan: Beginning with two identical

plants of the same starting height and species. I will place one plant on the window sill and another plant in the closet. I will give each plant the same amount of water each day (15mL) I will measure the height every week on Fridays for one month

Scientific Method:5. Observe and record your data. Use

tables and notes to record observations and measurements.

In the box provided draw a sample table that you would use to record data

Scientific Method:

Height of Plants (CM)Date Plant A Window Plant B Closet

Scientific Method:6. Analyze & Interpret Results using

charts and graphs

Scientific Method:7. Conclusion:-based on observations and results-State whether your hypothesis was

accepted or rejectedEx: My Hypothesis is accepted because

the plant on the window sill grew 3 cm but the plant in the closet did not grow.

Do Now:• Take out your Homework • Do Now Worksheet on deskToday’s Aim: Experimental Design

& Interpolating Data

Experimental Design:

• When designing an experiment, a scientist must test only one factor at a time.

• Variable: one factor that can exist in differing amounts that is being tested.

Experimental DesignControl Group Experimental

Group-Constant conditions - Identical to the- Used for Consistency control group and to isolate the EXCEPT for one Variable variable being tested

-Used to generate

results.

Independent VariableThe variable that is changed by

the scientist. For example: amount of sunlight in our experiment

To ensure a fair test, a good experiment has only one independent variable. As the scientist changes the independent variable, he or she observes what happens.

Dependent Variable

The scientist focuses his or her observations on the dependent variable to see how it responds to the change made to the independent variable.

For example: the growth of the plant

The new value of the dependent variable is caused by and depends on the value of the independent variable

Contols

A condition that is kept constant among groups in an experiment.

For example: The amount of water given to each plant

Do NowTake out “Saving Fred” lab, Pass up

procedure

Focused Free Write in class notesWhat is a line graph? Why are they so

important in science? What are some key elements that all line graphs must have?

How to make a graph!It's probably better to do a graph in

pencil first, then in pen.

How to make a graph!• 1. Collect your data. After you

have it all in one place, you should have one independent variable (like time) and one dependent variable (like something you measure as a function of time).

Making a Graph• Here are some points we will use as

an example; we've measured position of a ball as a function of time:

time (s) position (cm) 1 3.0 2 5.5 3 7.5 4 9.0 5 10.0

Making a Graph2. Determine the range of your

data. In order to determine how big a graph to make, we need to determine how much the numbers vary. In this case, time varies from 1 to 5 seconds, and position varies from 3.0 to 5.3 cm. We have to make sure that there is enough space on the graph to fit all the data

Making a Graph3. The independent variable (time,

in this case) will go on the x-axis (the one parallel to the bottom of the page), and the dependent variable (position, in this case) will go on the y-axis (parallel to the left hand side of the page). So, draw axes that are big enough for all the data.

Making a Graph4. Give your graph a Title. Titles of

graphs are usually "Y versus X"; so in this case, our title is "Position versus Time." (NOT position divided by time, or position minus time.)

Making a Graph5. Label your graph and your axes.

THIS IS VERY IMPORTANT! When presented with your graph, other people should be able to figure out what is plotted without asking you.

Making a Graph6. Labels on the axes must have

units! So, in this case, the label on the x axis (the one on the bottom) should be "Time (seconds)" and the label on the y axis (the one on the left) should be "Position (centimeters)."

Making a Graph7.Remember to write the numbers

on the graph, too. The numbers should be evenly and logically spaced - what I mean by this is the following: for our position data here, the y-axis should be marked off in increments like (1,2,3,4,5,6) or (2,4,6,8), NOT (1.3, 2.6, 4.8,...) or anything else weird.

Making a Graph8. Plot your data. Now, go ahead

and place your data points on the graph. Make them big enough to be seen, but not big enough to look like you were eating pizza while making your graph.

Making a Graph

9. CONNECT THE DOTS! THE ORIGIN IS NOT ALWAYS INCLUDED AS A POINT! Now you're done with your graph, but you're not finished yet.

Making a Graph

10. Think about what your graph means. What type of relationship do the variables have?

time (s)

position (cm)

1 3.02 5.53 7.54 9.05 10.0

  

         

  

         

  

         

  

         

  

         

  

         

  

         

  

         

Use the directions on the previous page to construct a graph. Here are some points we will use as an example to draw a graph; we've measured position of a ball as a function of time:

Graphing Terms• Interpolate: estimating information

within a graph (within the range of data given)

• Extrapolate: extending the graph to estimate information (outside the range of data given)

Questions1. I nterpolate the position of the ball at 2.5 seconds: ______ 2. I nterpolate the position of the ball at 4.5 seconds: ______ 3. Extrapolate the position of the ball at 6.0 seconds: ______ 4. Extrapolate the position of the ball at when it stops moving: ______ 5. Describe in words how the position of the ball is changing with time:

__________________________________________________________________________________________________________________________

6. What is the variable used to describe the relationship between position and time? _______________

7. Use the graph to explain how this variable of “speed” changes in this experiment._________________________________________________________________________________________________________________

8. What is the independent variable? _______________ dependent?_____________

Do Now:-Take out

Homework-Explain in a full

sentence the meaning behind this graph. Compare and Contrast data set 1 and data set 2

Temperature Vs Time

Time (min)

Tem

pera

ture

(˚

C)

19. Graphing• Direct Relationship: both

variables “move in the same direction” They both increase or both decrease. As time increases, the temperature increase.

Inverse Relationship• Variables “move in opposite

directions”. One variable goes up and the other goes down. Example: as temperature increases, density decreases

• One variable changes, but the other remains the same. As time increase the size of earth remains the same.

Cyclic: repeats at known intervals.Ex: As time goes on the hours of daylight increase then

decrease at a predictable rate.

Line Graph

Equal Value

Circle Graph (Pie Graph)• A=50% B=25% C=12.5% D=

______

B

A

C

D

Bar Graph

Do Now:-Find the folder with your name on it, this is

your seat. Do NOT move or open the folder.

-Put all belongings on a LAB table-Take out a pencil -Take out a calculator-Be silent and have a big smile on your face

when I walk in the room.-Relax, if you studied you will do AWESOME!

Rate of change• How fast did the change happen?

• How much a measurable aspect of the environment, called a field, is altered over a given amount of time – years, hours, or seconds.

The steeper the slope the faster the rate of change!

If the slope is constant, the rate of change is also constant

If the slope is exponential or curved, then the rate of change is not constant!

A flat horizontal line, means the that the value is constant over time and not changing at

all

Cyclic Change:• Changes that repeat over and over in

a known period of time.

• Examples are: seasons, sun motions, moon and tides

• Most changes are cyclic and they are very good to use when we are trying to make predictions

Non-cyclic Changes:• Changes that do not repeat at all or

do not repeat in a known period of time.

• Some examples of these are:

• Earthquakes and Hurricanes.

Formula:• Change in field value Change in time•

• Formula is on p. 1 in ESRT

Rate of Change questions

• 1. If the greenhouse effect causes the Earth's average temperature to increase by a total of 3°F between the years 1960 and 1990, what is the rate of temperature change in degrees per year (°F/year)?

Rate of Change questions

• 2. After a series of earthquakes, a landsat satellite computes that California is 15 cm less wide than it was 3 years ago. What is the rate of change of California's width?

Rate of Change questions

• 3. As hurricane Felix neared the U.S. coast, air pressure dropped from 996 millibars to 980 millibars in 8 hours. Calculate the rate of air pressure change in mb/hour.

Matching Graphs to Situations:

Interpreting Graphs

SBN 2003

Select the graph that best fits the situation described.The answer will appear with

one click.

Riding a bicycle up a steep hill and down the other side

Answer : 1

The amount of gasoline used while traveling on level ground

Answer : 3

A candle burning

Answer : 1

A car stops at a stop sign and then continues the drive

Answer : 1

A wagon is pushed and then coasts to a stop

Answer : 3

A truck slows down and then speeds up

Answer : 1

A marble that rolls until it stops

Answer : 1

A unoccupied tricycle rolls down a hill into an oak tree

Answer : 1

The level of water in a river over the year with rains and dry spells

Answer : 2

A yo-yo moving rhythmically up and down

Answer : 1

The ocean waves washing away a sand castle on the beach

Answer : 3

Income earned from an hourly wage job

Answer : 2

The growth of a tree over several years

Answer : 3

A dog sleeping in the shade

Answer : 3

The area of a square

Answer : 2

After the plug is pulled, the water draining from a bathtub

Answer : 2

A speeding car crashes into a solid brick wall

Answer : 3

Waiting to land, an airplane circles at a constant speed

Answer : 2

The seat of the ferris wheel at the county fair

Answer : 2

Do Now:• Take a Lab

from the Do Now Desk!

• Begin reading the directions quietly to yourself

Skittles

Graphing

Lab Today!

Do Now: Take a Goal/Review Sheet

from the Do Now Desk

Station Group

1 Anthony & Jane2 Juilet & Ryan3 Joe Kim & Edward4 Enis & Kayla5 Joe N. & Erick 6 Byron & Hye Jun7 Noah & Emma8 David & Julia9 Sienna & Gabby & Diego

Station Group

1 James & Vera2 Kristen & Roni3 Kerry & Nikki4 Corinna & Victor5 Lisa & Charles6 Olivia & Joseph7 Alejandro & Blake8 Yessica & Rachelle9 Stephanie & Ari10 Paola & Jason11 Keller & Madeline

Do Now: Clear your desk

you need a pencil and a Calculator

Sit in Test Seats

4. CLASSIFICATION:• To put things into groups. • We can organize or classify objects

according to some pattern or trend or common characteristics.

Classification• The purpose of classifying is to

organize creatures into four different groups. Remember that creatures can only end up in one group at the end.

• After you divide them in to two groups, they can not cross over when you divide them again.

Rules to Classification• Start each question with “ Does it have

___.”

• -Do NOT use size, color or behavior.

• Don’t use the same question twice• - Good examples are: Does it have wings? Does it have more than two legs? Does it have feathers? Does it have Antenna? Does it have segments? Does it have scales?

Rules to Classification• 6) Do NOT use the same question twice• 7) Do NOT use size, BAD EXAMPLE #1: “Is

it big?” • 8) Do NOT use color. BAD EXAMPLE #2:

"Is it blue?"• 9) Do NOT behavior or function, BAD

EXAMPLE #3: "Can it fly?"• 10) Do NOT use environment, BAD

EXAMPLE #4: "Does it live in the ocean?"

Rules to Classification

Classif y these creatures: Question # 1: ____________________________________________________________

Yes: No:

Yes: No:

Question #3: ______________________________________________________________

Yes: No:

Question #2: ______________________________________________________________

Don’t cross this line!

Do Now:• Take both sheets on the Do Now

Desk• On the back of the classification

worksheet write the rules for classification that we learned yesterday.

Do NOW: Measurements Worksheet on Do Now Desk

a. What are some measurable properties?

Think on a daily basis, what might be some of the things

you measure?

-Mass -Area-Temperature -Volume-Density -Pressure

b. How do we make measurements?

• Our senses are limited by how sensitive or by how accurate they are. To get more detailed information, we use instruments, such as rulers, thermometers, x-rays and telescopes

c. Metric System & Unit Conversion

• The fundamental units of the metric system are:

For Mass______________________ • For Length

______________________• For Liquid Volume

________________

Grams (g)

Meters (m)milliliters (mL)

Prefix Fun!• By changing the prefix used with

each unit you can change the size of the unit. We will use the following prefixes. (There are others for both larger and smaller units.)

Hecto- (102)

Deca- (101)

Kilo- (103)

Centi- (10-

2)

Milli-(10-3)

Deci- (10-1)

Basic Unit (100)

Prefix Fun!• You can

remember this using the following sentence:

• King Henry died, drinking chocolate milk

Hecto- (102)Deca- (101)

Kilo- (103)

Centi- (10-2)Milli- (10-3)

Deci- (10-1)Basic Unit (100)

• To convert from any unit to any other unit count how many spaces are between them and move the decimal point that far in the same direction.

Let’s look at the meter stick! How many meters (m) are in a meter (m) stick?___

How many centimeters (cm) are in a meter (m)? ___________

1

100

• How many millimeters (mm) are in a centimeter (cm) ?__________ Now if there are 100 cm in a meter and 10 mm in a cm how many mm are in a m? __________

10

1000

• Decimals are used because they are easier to convert than fractions! In the metric system we use abbreviations! Let’s fill them in below!

Length ___ MassLiquid Volume meter__________ gram_______

liter________ millimeter_______ milligram______milliliter______ centimeter_______ ------------ ------------kilometer_______ kilogram______ kiloliter______

m g Lmm mg mLcm

km kg kL

Please complete the practice questions 1-15

Do Now• Open up to classwork section, and

complete the following:Focused Free Write:Why do scientist round answers to math equations? What is the purpose? What are the rules of rounding?

6. Rounding:• The first step in rounding is figuring

out what place to round to and where that place is located. You must remember these place values:

• 2 , 6 4 3 , 9 7 5 , 8 6 4 . 9 3 1

Thou

sand

ths

tenth

sHu

ndred

ths

onesten

s

Thou

sand

shu

ndred

s

Ten t

hous

ands

Hund

red Th

ousa

nds

Ten M

illion

smilli

ons

Hund

red m

illion

s

Billio

ns

Rounding Procedure:• Step 1: Find the location of place that

you are asked to round to. Lets call it: Sparky.

• Step 2: Look at the number to the right of this place lets call it the Boss.

• Step 3: If the boss is a 4 or lower, leave Sparky alone. If the Boss is 5 or higher, round the Sparky up one value.

Rounding Procedure:• Here is a rhyme to help you

remember:• “Four and below, let it go. Five and

above give it a shove”• For Example: Round 7.289 to the

nearest tenth: Answer: 7.3• Now complete practice problems 1-9!

Do Now• Have your homework on your desk• Take out graduated cylinder

worksheet• Focused Free Write: What is mass?

Do Now: In class notes Section, Round the following

to the nearest TENTH!

1) 8.6782) 99.0123) 784.5554) 10.995 )0.3567

= 8.7= 99.0=784.6

= 11.0= 0.4

• Also, take out HW, add 6pts on point chart if complete

Check your answers1. 88 mm = 8.8 cm2. 5.7 km = 5700 m3. 18,500 ml = 18.5 L4. 15,300 g= 15.3 kg5. 0.023 kg= 23,000 mg 6. 0.3 cm = 3.0 mm 7. 5,287,945 mm=

5.287945 km8. 12,300 ml = 12.3 L9. 0.007 km = 7,000

mm10. 0.008 km = 800 cm

Check your answers11) 6.78: 6.812) 8.210:8.213) 3.0682: 3.114) 82.921: 82.915) 15.23: 15.2

16) 75.023: 75.0217) 46.9: 46.9018) 32.97045: 32.9719) 99.9999: 100.00

20) 1.65656565: 1.65721) 100.967: 100.967 (already there)22) 0.011223: 0.011

Check your answers20) 1.65656565: 1.65721) 100.967: 100.967 (already there)22) 0.011223: 0.011

23) List two numbers that would round to 8.7: 8.745 & 8.689

24) Explain why 7.93 rounds down to 7.9:The number to the right of the tenth’s place

is less than 525) Explain why 2.85 rounds up to 2.9:The number to right of the tenth’s place is

greater or equal to 5

What is MASS:• Is the amount of matter in an object.

• It is how much “stuff” the object is made of, the number of molecules in it.

How do we measure Mass• Can we count the atoms? One by one?

LolNope! Instead we use a triple beam balance which gives us a value usually in grams.

Let’s click here for an interactive triple beam balance!

Is Weight the same as Mass?

Weight is NOT the same as mass, but weight is used to measure the mass of an object on the Earth. Think about what would happen if you weighed your self on the moon. You would weight less because there is less gravity pulling you down onto the scale, even though your mass did not change.

Let’s check our our weight on the MOON!!!

8. Temperature:• It is the amount of heat energy an

object has.• Typically the faster the molecules

vibrate with in a sample of matter the hotter it is.

English Units: Fahrenheit Degrees (F°)• Water Freezes : 32°F.• Water Boils: 212°F.

Metric Units: Celsius Degrees (°C)• Water freezes: 0°C.• Water boils: 100° C.

Kelvin Units (K)• Absolute zero: 0 Kelvin’s• Water freezes: 273 Kelvin’s• Water boils: 373 Kelvin’s

• The lowest possible temperature and occurs when ALL heat is removed.

• It is equal to -272°C.

ABSOLUTE ZERO:

What are three states, or phases of matter?

• Solid (ice) Liquid (water) Gas (water vapor)

9. What variable determines the different phases? Temperature

11. Area:• The amount of space a 2-dimensional

object takes up• For squares and rectangles area is equal

to: L

x W• L: Length, the longer dimension of an 2 D

object usually measured in meters, centimeters or millimeters.

• W: Width, the shorter dimension of a 2D object.

• Note that the units will always end up squared! Example: 4mm x 2mm = 8mm2

11. Area:Let’s practice using the following steps:• Step 1: Write the formula Example: Area = L x W

• Step 2: List all the variables including the unknown, WITH UNITS.

Example: L = 4mm W= 2mm A= ?

11. Area:Let’s practice using the following steps:• Step 3: Plug in the numbers,WITH UNITS.

Example: A=4mm x 2mm

• Step 4: Calculate WITH UNITS. Example: A= 8mm2

• Practice the two examples on your own!

Do Now: Take one ruler and one object from the box on the front table.

Use the ruler to find the volume of the object you choose. If you can not use the ruler to find the volume, explain how you could.

10. Volume:• The amount of space an

object takes up• For solid cubes and boxes,

Volume is equal to: L x W x H Depending on the size of the object the units may be either cm3 or m3.

10. Volume:• But for liquids, volume is measured

in liters using a beaker or graduated cylinder. There two rules:

1. Always read it at eye level

This is a beaker!

10. Volume:• 2. You must read the meniscus to

obtain an accurate result. Due to cohesion (sticky) properties of fluids, the edges of the fluid touching the glass will slightly rise.

Meniscus = 73 mL

10. Volume:It is easier to measure

irregular shaped objects using fluid displacement. In order to measure this irregularly shaped rock you would drop it in a beaker filled with water and measure the change in volume.

What factors affect Volume?• 1)Temperature• Heating a material will cause it to expand

and take up more space because the molecules need more room to move around. Therefore increasing temperature will increase volume.

• _________________• Cooling a material will result in the opposite.

So decreasing temperature will decrease volume. ____________________

• Think about how your rings fit in the winter… they seem to be bigger!

T V

T V

What factors affect Volume?• 2) Pressure:• Increasing pressure will force molecules

closer together there by decreasing volume. ______________________

• Decreasing pressure will allow molecules to spread out and take up more space thereby increasing volume. _________________

• Let’s model this with a sponge. P V

P V

This week’s HWMonday: Measurement worksheet and

study for quizTuesday: Density Homework WorksheetWednesday: No HWThursday: Graphing WorksheetFriday: No HW

Extra Help: Today after school and tomorrow morning

11. DENSITY• The amount of matter (mass) in a

given amount of space (volume).

• It tells us how tightly packed the molecules are, or how close to each other they are.

• If they are packed tightly, the density is high.

DENSITY UNITS• The unit for measuring density is grams per cubic centimeter, or g/cm³

• Density = Mass Volume M

D V

Step 1• Write the formula

• Example: Density = Mass/Volume or D=M/V

Step 2• List all the variables including the

unknown, WITH UNITS.

• Example: D=?M = 38.0gV = 12.0cm3

Step 3• Plug in the numbers, WITH UNITS.

• Example:D=38.0g/12.0cm3

Step 4• Calculate WITH UNITS. • Example:

D=3.2g/cm3

ExampleIf an object has a mass of 13.4 grams and a volume 5.7 cm3 what is the density?

Solution:

Let’s Practice !!!• Please complete the worksheet

Do Now:Take out HW• Quietly look over your notes in prep

for you quiz• You need a calculator

Do Now: Draw this in your class work section

Beaker filled with water: Density = 1.0 g/cm3

D= 1.0 g/cm3

D= 0.8g/cm3

D= 0.2 g/cm3

D= 0.5 g/cm3

D= 3.0 g/cm3

D= 1.5 g/cm3

• Each pure substance has its own particular density and it can be used to help identify that material at room temperature.

• For example, liquid water has a density of 1g/cm³ because 1cm³ of water weighs 1 gram. One cm³ of water also occupies 1ml.

• solid quartz has a density of 2.7 g/cm³ Mixtures do not have a precise density.

-Fluids tend to layer based on their density, with less dense fluid on top of more dense fluid. Can you think of any examples?

Let’s check out this video!• http://www.eram.k12.ny.us/education/components/docmgr/default.php?sectiondetailid=17500&fileitem=4738&catfilter

=445

Oil and Vinegar!

Factors that affect Densitya. Temperature• Cooling a material causes its

molecules to move closer together, making its volume decrease and causing its density to increase.

• Heating a material causes its molecules to move apart making its volume increase and causing the density to decrease

• Note that Mass is staying the same!!!

T VD

TVD

So why does density matter?

If a warm gust of wind meets cold air, will the warm air go above or below the cold air?• Since hot air is less dense it will rise!

• And Cold air sinks because it is denser than warm air

• This happens when you boil water

This rising and sinking of fluids due to density and

temperature differences is called…

A CONVECTION CURRENT!!!We will touch upon this concept

many times through out the year

Factors that affect Density:b. Pressure

• Increasing the pressure (squeeze) on a material causes its molecules to get pushed closer together, decreasing the volume, making the density increase.

• Decreasing the pressure causes the opposite effect, since molecules move further apart, it becomes less dense.

• Again, note mass remains the same!P VD

P VD

Do Now: Take out Density of GUM LAB turn to data.

• Focused Free Write: Take a look at my awesome Lava Lamp. Why are the colors separated? Why do the blobs move rather than

settle? What processes in earth can we relate this

phenomenon to?

15. Density at Different Phases• As a material is heated, it changes

from solid to liquid.

• More heat changes the liquid to gas. The molecules move farther apart, so the volume increases, causing the density to decrease.

• Solids are most dense, gases are least dense

The Only exception to this rule is water

• As water cools, its volume decreases until it reaches 4° C.

• As it cools from 4° C to 0° C, its volume actually increases, so it becomes less dense again.

• Water is most dense at 4°C, but is still a liquid.

• This is due to my buddy Mr. Hydrogen Bond, you will meet him in Chemistry

• Water at 0°C is solid ice, but is less dense than water, so ice floats!!

• Water is the only material whose solid form will float in its liquid form.

• This is why the top of a puddle, or a

lake freezes first.

16. Does size affect density of an object?

• You can NEVER change the density of a material by cutting it into pieces.

• Since change both volume and mass, the ratio will remain the same, therefore each small piece will have the same density as the original large one.

17. Let review some crucial relationships!!!

• Temp. Density

• Temp. DensityYou must understand and know these by

heart!!!

Let review some crucial relationships!!!

You must understand and know these by heart!!!

• Pressure Density

• Pressure Density

• As temperature _________________, Density _____________ this is a ________________ relationship

• As temperature _________________, Density _____________ this is a ________________ relationship

As pressure _________________, Density _____________ this is a ________________ relationship

As pressure _________________, Density _____________ this is a ________________ relationship

Do Now: Copy HWFocused free write: Why does

ice float? Is the Dad’s explanation correct?

Do Now: Draw how each liquid would layer if your poured them into the big cylinder

Liquid C

D= 5.0

g/mL

Liquid D

D= 0.5 g/mL

Liquid B

D= 3.0 g/mL

Liquid A

D= 1.5 g/mL

Density Quiz Tomorrow10 multiple choice questions

5 short answer question-Know how to draw how an object will float in water

based on it’s density-Know how liquids will layer based on density-Know why ice will float in water-Know how to calculate densityKnow relationships between…-Density and Temperature-Density and Mass-Density and Pressure