wacky soda demo why? mystery liquids #1 did you discover more than one combination that would work?...
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Wacky Soda Demo
WHY?
What have we experienced?
Mystery Liquids #1Did you discover more than one combination that would work?
What do you think the liquids are?
Mystery Liquids # 2What do you think keep the liquids separate?
Which layer was just water?
Give an example of two gases with different densities.
How do you know they have different densities?
In your science notebook….Today’s date: 3/21/2012
Title: Lava Lamp & Density
Draw a lava lamp and describe how you think the lamp works inside. (HINT: think about our density discussions)
Substance Mass (grams)
Volume (cm3)
Density (g/cm3)
Bar A 110 100
Bar B 95 100
Water 100g 100 cm3 1.0 g/cm3
Problem: Two different bars of soap are being investigated by a group of students. The students measured the mass and volume of each bar and recorded it below.•Calculate the density of each bar of soap. Show your work.
Homework Review
1.1 g/cm3Density =M/VBar A: 110g/100cm3 = 1.1 g/cm3
Bar B: 95g/100cm3 = 0.95 g/cm3 0.95 g/cm3
A
B
Step 1Read the problem.
Step 2Write the formula. “Copy”
Step 3Replace the words with the numbers and units.“Substitute”
Step 4Divide mass by the volume “Evaluate”
Step 5 Write the answer and include units.
If 96.5 grams (g) of gold has a volume of 5 cubic centimeters (cm3), than what is the density of gold?
Density = Mass/Volume
Density = 96.5 grams/5 cm3
Type in 96.5, hit ÷Type in 5, hit = 19.3
Density = 19.3 g/cm3
Finding Density using Math
Substance
Mass Volume
Formula/My Math Density
Air .026 g
20 cm3
Gasoline 21.0 g
30 cm3
Wood (oak)
34.0 g
40 cm3
Water (ice)
36.8 g
40 cm3
Water (liquid)
1.0 g
1 cm3
Aluminum
96.5 g
35 cm3
Steel 273.0 g
35 cm3
Silver 367.5 g
35 cm3
Gold 675.5 g
35 cm3
Platinum 752.5 g
35 cm3
Weight Volume Formula/My Math
Density Substance
1 .35 g
15,000 cm3
G
2.67 g
15,000 cm3
G
19.5 g 15,000 cm3
G
3200. g 2000 cm3
L
2000. g 2000 cm3
L
3600. g 2000 cm3
L
1800. g 2000 cm3
S
1840. g 2000 cm3
S
5600. g 3500 cm3
S
1. Density is a property of all matterMatter is any object that takes up space and has mass
2. Density measures how tightly packed the mass is in an object
Density Facts
3. Density measures how much mass is squeezed into a space.
4. A dense object feels “heavy” for its size. A one –pound rock and a one-pound pillow have the same mass, but the rock is a lot denser; the rock takes up less space.
5. Densities of fluids, liquids and gases, can be compared usually by which fluid floats and which fluid sinks.
6. Densities can be measured by using MATH
The formula for density is d = densitym = mass (grams)v = volume (ml or cm3)
Density practice
Material Mass Volume Formula Density
Wood (oak) 34.0 g 40 cm3
Ironwood 51.2 g 40 cm3
Water 40 g 40 cm3
0.85g/cm3
1.28 g/cm3
Melting Ice Cube Lab
What happened to the ice when you first placed the cubes in the jars?
Describe the pattern the food color made in each of the jars… Why do you think there was a difference in the pattern?
Why did the food coloring ‘drop’ to the bottom of the fresh water jar?
Why did the food coloring stay on top of the salt water jar?
Why did the ice cubes stop melting in the salt water jar?
What will cause the salt water jar to eventually mix?