Bellwork
1-6-16
Predict what will happen when 3
pennies are placed in vinegar for
24 hours.
What type of change will occur?
(physical or chemical)
Changing Change
• The teacher will place a folded paper towel
in a small pie pan.
• Pour vinegar into the pie pan until the
entire paper towel is damp.
• Place Three shiny pennies on top of the
paper towel.
• Put the pie pan in a safe place.
• Wait 24 hours.
Objectives
• Do I recognize that all matter consists of atoms? SPI
0807.9.1
• How can I compare the particles in a solid, liquid, and
gas? SPI0807.9.6
• Can I calculate the density of an object given its mass
and volume? SPI 0807.9.7
• TOC:
• #. Density triangle
• #. Chapter 7 notes
• #. Density Problems #1
#. Density TRIANGLE
Write this in your SNB
Density: the amount
of matter (mass) in a
given amount of
space (volume)
Units:
g/mL
g/cm3
D
m
Mass: the amount of
matter in an object
Units: kg, g,
mg
v
Volume: the amount
of space an object
takes up
Units:
kL, L, mL
km3, m3,
cm3
#. Chapter 7 notes
Identify six examples of physical
properties of matter.
• Physical properties of matter can be observed without
changing the identity of the matter.
• 1. Density - the amount of matter in a given space, or volume.
• 2. Solubility – the ability of a substance to dissolve in another.
• 3. Ductility – the ability of a substance to be pulled into a wire
• 4. Malleability – the ability of a substance to be rolled or pounded
into thin sheets
• 5. State – physical forms of matter
• 6. Thermal conductivity –transferred heat
Describe how density is used
to identify substances.
• To find an object’s density (D), first measure its mass
(m) and volume (v). Then use the following equation:
D = m/v
• Explain what happens to matter during a physical
change.
• A physical change affects one or more physical
properties of matter. (the identity doesn’t change)
• Examples of different physical changes: melting ice,
cutting your hair, sanding wood, crushing a can,
mixing oil and vinegar
Describe two chemical
properties.
• Chemical properties describe a substance
based on its ability to change into a new
substance with different properties.
• Chemical properties include:
Flammability – ability to burn
Reactivity with water, acid, and
oxygen causing a change in the
identity of a substance
Chemical properties can only be observed
when a chemical change takes place.
Explain what happens
during a chemical change.
• A chemical change occurs when one
or more substances are changed into
new substances with different
properties.
• Clues to chemical changes: fizzing
and foaming, color change,
production of heat, light, sound or
odor
• Distinguish between physical and
chemical changes.
• Physical changes can be reversible by
physical means.
• Chemical changes cannot be undone
by physical means.
#. Density Problems #1
• Answer the items on the
Density Problems #1
Worksheet.
Density Problems # 1
Answers
• 1. Which square is the densest? Why?
•
•
2. Which square is the densest? Why
•
•
•
•
Density Problems # 1
Answers
• 3. What is density? The amount of matter
(mass) in a given space (volume)
• 4. What is the formula for Density? D = m
/v
• 5. What are the units for Density? g/mL or
g/cm3
• 6. Why are these units for density? The
units represent the equation that you are
working-difference between mass and
volume.
Density Problems # 1
Answers
• 7. Frank has a paper clip. It has a mass of 9g and
a volume of 3cm3. What is its density?
9 g ∕ 3 cm3 = 3 g/cm3
• 8. Frank also has an eraser. It has a mass of 3g,
and a volume of 1cm3. What is its density?
3 g ∕ 1 cm3 = 3 g/cm3
• 9. Jack has a rock. The rock has a mass of 6g
and a volume of 3cm3. What is the density of
the rock?
6 g ∕ 3 cm3 = 2 g/cm3
Density Problems # 1
Answers
• 10. Jill has a gel pen. The gel pen has a mass of 8g
and a volume of 2cm3. What is the density of the
rock?
•
8 g ∕ 2 cm3 = 4 g/cm3
• 11. Alicia has a watch. It has a mass of 4g and a
volume of 2cm3. What is the density of the watch?
• 4 g ∕ 2 cm3 = 2 g/cm3
• 12. Mia has a wallet. It has a mass of 15g and a
volume of 5cm3. What is the density of the wallet?
•
15 g ∕ 5 cm3 = 3 g/cm3
Density Problems # 1
Answers
• 13. Which layer has the highest density? 4
• 14. Which layer has the lowest density? 1
• 15. Imagine that the liquids have the
following densities:
Which number would go with which layer?
•
4 10g/cm3
2
5g/cm3
•
1
3g/cm3
3
6g/cm3
Density Problems # 1
Answers
• 16. Which liquid has the highest
density? 3 – syrup
• 17. Which liquid has the lowest
density? 1 – oil
• 18. Which liquid has the middle
density? 2 – water
Density Problems # 1
Answers
• Liquid Layers – Check out picture 3:
• 19. Imagine that the liquids on the right have
the following densities: Which number
would go with which layer?
• 6
15g/cm3
• 4
10g/cm3
2
5
7g/cm3
1
3g/cm3
12g/cm3
3
9g/cm3
Density Problems # 1
Answers
• 20. What is the formula for density?
•
D=m/v
• 21. What are the units for density?
•
g/mL or g/cm3
• 22. What happens if you pour together liquids
that have different densities?
•
They will separate into layers with the least
dense on top and most dense on the bottom
Density Problems # 1
Answers
• 23. Will the liquid on the top have the
highest or lowest density?
•
Lowest
• 24. Will the liquid on the bottom have
the highest or lowest density?
•
Highest
Density Problems # 1
Answers
• 25. Jake has a book, a ruler, and a balance. How can
Jake find the density of the book with the tools he has?
(Hint: Explain HOW you use EACH tool for your
answer to be correct!)
•
Jake would find the volume of the book using the
ruler, than he would multiply the L x W x H in cm3.
•
Jake would find the mass of the book by
measuring it on the balance in g.
• Lastly, Jake would find the density by D = m / v in
g/cm3.
Exit Ticket
Does a display of
fireworks represent a
physical or chemical
change?