Transcript Pure Substances & Mixtures Notes

QOD #26
• What happens to water when it
starts to boil? (What do you see
happening?)
QOD#27
How are atoms and cells
different?
• Atoms are much much smaller than
cells.
• Cells are the basic unit of all living
things and atoms are the basic unit for
all things (matter).
• Atoms make up all the parts of a cell.
States of Matter Notes
How are atoms and cells
different?
• Atoms are much much smaller than
cells.
• Cells are the basic unit of all living
things and atoms are the basic unit for
all things (matter).
• Atoms make up all the parts of a cell.
3 (most common) States of Matter
SOLID
• Molecules
are close
together
and vibrate
in place
LIQUID
• Molecules
are close
together but
slide past
each other
• Take up
space of
container
GAS
• Molecules
move very
quickly
• Molecules
are far apart
• Take up
space of
container
Our examples of molecules moving
Solid
Liquid
Gas
A knife slicing Food coloring Dust particles
into butter. in water.
in the air.
We simulated the
movement of gas
molecules with
the bouncy balls.
Changes in State
• Melting – solid to a liquid (add heat)
–Water freezes and melts at 0ᵒC/32ᵒF
• Freezing – Liquid to a solid (lose heat)
Water freezes and melts at 0ᵒC/32ᵒF
• Evaporation – liquid to a gas (add heat)
– Water boils and evaporates at 100ᵒC/ 212ᵒF
• Condensation – gas to a liquid (lose
heat)
• Sublimation – Solid to a gas (skips liquid
stage)
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(Challenge only)
Process
Exothermic
Endothermic
•
•
Heat exiting a substance
Ex: water freezing;
condensing
Physical change
•
•
Chemical reaction where
energy is released in the
form of light or heat
Feels hot – chemical bonds
forming
Temp. change - warmer
Ex: Calcium & water
•
•
Reaction
•
•
•
•
•
•
•
•
Heat entering a substance
Ex: water evaporating;
melting
Physical change
Chemical reaction that
absorbs energy from its
surroundings
Feels cold – chemical
bonds breaking
Temp. change - colder
Ex: Vinegar & baking soda
Regular Science
Process
Exothermic
Endothermic
•
•
Heat exiting a substance
Ex: water freezing, water
condensation
Physical change
•
•
Chemical reaction where
energy is released in the
form of light or heat
•
•
Reaction
•
•
•
Heat entering a substance
Ex: water evaporating, ice
melting
Physical change
Chemical reaction that
absorbs energy from its
surroundings
Feels cold
Kinetic Molecular Theory
(The short version…)
• Small particles make up all matter.
• These particles are in constant, random
motion.
In a gas:
• The particles collide with other particles, other
objects, and the walls of their containers.
• When particles collide, no energy is lost.
Endothermic Reaction
(Vinegar & Baking
Soda)
Time
(sec.)
0
15
Temperature (C)
Exothermic Reaction
(Calcium & Water)
Time
(min.)
0
1
30
45
60
75
2
3
4
5
90
6
Temperature (C)
QOD #28
• When you add heat to ice and it
melts, is that an endothermic or
exothermic process?
Goal 1 & 2 Formative Assessments
QOD #29
• What four pieces of information
appear in each box on a periodic
table?
Periodic Table of the Elements
Notes
Atomic Number
Element Name
6
C
Carbon
12.0
Chemical
Symbol
Atomic Mass
or Mass
Number
Copy this chart in your notes. Use the
periodic table to fill in the missing info.
Element Name
Atomic Number
Chemical Symbol
Atomic Mass
Hydrogen
Fe
8
12.0
Aluminum
QOD #30
• Is water freezing an exothermic or
endothermic process? Explain why.
Pure Substances & Mixtures Notes
Matter
Pure Substances
-Cannot be physically
separated
Elements
-simplest
substance found
in nature
Examples:
• Aluminum
• Oxygen
Compounds
-Two or more
elements are
chemically
joined
Examples:
• Water – H2O
• Salt – NaCl
Mixtures
-Can be physically
separated
-when there are 2 or more
substances
Solutions
Visible
Mixtures
-All parts look
the same after
mixed
-Two or more
parts are visible
Examples:
• Salt Water
• Milk
Examples:
• Pizza
• Salad
Item
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Pure Substance/
Mixture
Explanation
Item
Pure Substance/
Mixture
Explanation
1. Kool-Aid
Mixture
Solution of water & mix; can be separated
2. Gold necklace
Pure substance
Gold is an element - Au; cannot be physically sep.
3. Candy
Mixture
Sugar, chocolate, etc.; can be separated
4. Iron nail
Pure substance
Made of iron – element Fe; cannot be physic. sep
5. Soap
Mixture
Solution of ingredients; can be separated
6. Dry ice
Pure substance
Compound - Frozen CO2 ; cannot be phys. sep.
7. Salt
Pure substance
Compound - NaCl; cannot be physically separated
8. Salad dressing
Mixture
Multiple ingredients; can be separated
9. Water
Pure substance
Compound − H2 O; cannot be physically sep.
10. Helium
Pure substance
Element – He; cannot be physically separated
11. Soup
Mixture
Lots of ingredients; can be separated
12. Quartz
Mixture
Visible pieces of rock; can be separated
Making Solutions
To dissolve: to form a solution by mixing evenly
An object/substance is…
…soluble if it dissolves when mixed.
ex:
…insoluble if it does not dissolve when mixed.
ex:
Solvent – substance that dissolves another
substance to make a solution
Solute – substance being dissolved
Ex:
Chocolate syrup
SOLUTE
Milk
SOLVENT
(Identify the solvent and solute in the example
below)
Ex: Making Kool-Aid
Water:
Sugar mix:
QOD # 31
What are two differences
between a pure substance and a
mixture? (Hint: Don’t just sit
there…look at your notes!)
Use PQPA!
Making Mixtures
(challenge did this as a demo in class & others as a take home EC lab)
Substances
Prediction
– will it
dissolve?
Solute
Solvent
Soluble or
insoluble?
Qualitative Observations
– What happened?
What did you see?
QOD #32
Complete the following information using your
periodic table for…
• Carbon:
– Chemical Symbol = _______
– Atomic Number = _______
– Atomic Mass = ________
• Silicon:
– Chemical Symbol = _______
– Atomic Number = _______
– Atomic Mass = ________
Element Trading Cards
• Go to rathjenscience.weebly.com and click on
Useful Links.
• Use the NOVA ELEMENTS link to jump to the
Nova Elements site. (If you are prompted to
download a flash player – do it.)
• Fill out the player cards for 4 elements of your
choice. (Do a good job or no one will want to
trade you!
• Explore the rest of the site!