Bell Work – write question, answer and explanation 9-24-11 A substance is mixed into a solution. If there is no chemical reaction, what will happen when the liquid is evaporated out of the mixture?

a. The container will be empty b. The container will have residue of the solid that was originally dissolved c. The mixture cannot evaporate d. None of the above

Bell Work – write question, answer and explanation 9-28-11 Carbonation is mixing a gas into a liquid such as when soda pop drinks are made. Which answer is correct? Explain your answer.

a. This is a chemical change b. This is a physical change c. Gas cannot be mixed into a liquid d. The gas is the solvent and the liquid is the solute of the solution

Quiz 1. Which of the following is not an example of matter?

a. Air b. Liquid c. Love d. A pencil

Quiz 2. Chocolate is left in a car on a hot summer day. Which picture best represents the molecules of that chocolate?

a. b. c.

Quiz 3. Which answer best represents helium at room temperature? a. b. c.

Quiz 4. Which answer is not true about the molecules this picture represents?

a. The molecules are not moving at all b. The molecules are vibrating c. The molecules do not have enough energy to break away from each other d. This picture represents the molecules of a solid

Quiz 5. Which can be used as an example of the 3 most common states of matter changing phases in real life?

a. chocolate melting b. a popsicle freezing c. bread baking d. the water cycle

Quiz 6. Which vocabulary word describes a liquid changing to a gas?

a. melting b. condensation c. evaporation d. sublimation

Quiz 7. Water and salt are mixed in a solution. Which of the following can be used to separate the substances of that mixture?

a. melting b. plasma c. freezing d. evaporation

Quiz 8. Which of the following is not an example of a physical property?

a. Boiling point b. Volume c. The ability to burn d. Magnetism

Quiz 9. What is the name of the method that uses rates of solubility to separate substances? The individual colors used to make black ink can be discovered this way.

a. evaporation b. chromatography c. Sublimation d. photography

Quiz 10. When we separated the black ink, the blue color was on top? Why a. It is the hardest to dissolve b. It has less mass, so it floated to the top c. It is insoluble d. It is the most soluble

• • • • • • • • • • -0 = 30 -1 = 27 -2 = 24 -3 = 21 -4 = 18 -5 = 15 -6 = 12 -7 = 9 -8 = 6 -9 = 3 Grade Bonus +5

Quiz BONUS: Explain why the center of the Earth is thought to be made of solid iron and nickel instead of liquid or gaseous iron and nickel?

It is the hottest place in the Earth, so how can this be?

What is Matter?

Anything that has mass and takes up space.

STUFF!

What instrument is used to measure mass?

• A balance • Scales are used to measure weight.

What are some examples of matter?

• List some…… • What about air, is it matter? Does it have mass?

What are the three most common states of matter?

1. solid 2. liquid 3. Gas Lets demonstrate!!!!!!!!!

See particle movement for each phase

Demonstration • Lets create our own Human Molecules Demonstration!!!

2 other states of matter…..

• Plasma (super excited and super hot atoms) *examples: neon signs, ball lightening, stars • Bose Einstein condensate (super unexcited and super cold atoms) See States of Matter

The Water Cycle is an example of state changes in nature • • Water from Earth evaporates into water vapor – Because it heats up Water vapor condenses and forms clouds – Because it cools down • It can become ice, snow or hail if it cools enough Water precipitates as and it all starts over again!

Can you name other state changes we observe?

• • • Can you name other state changes we observe?

Chocolate in a hot car melts – Solid to liquid Will it become a solid again?

Is it still chocolate?

– Then it is still the same substance so it is a physical change.

• What about cheese, plastic, popsicles…?

The state of matter a substance is at room temperature is a physical property that can be used to identify the substance.

• • • What is water at room temperature?

What is plastic at room temperature?

What is helium at room temperature?

What causes the states of matter to change?

• • • ENERGY… Heat added changes a solid to liquid to gas Heat taken away changes gas to liquid to solid

What are the changes of matter called?

• • • • • Solid to liquid…..melting

Liquid to solid…..freezing

Liquid to gas…..evaporation

Gas to liquid….condensation

Solid to gas….sublimation

What determines how fast the state of matter changes?

• • • • • Pressure and heat The starting temperature The amount of the substance that undergoes change The amount of heat that is applied to the substance The surface area is another factor that determines how fast a substance will melt or boil.

How do we describe matter?

• • Physical properties Chemical properties

Physical properties • Properties that do not change the chemical nature of the substance Link

Physical Property Color, Shape, Length, Mass Volume Density solubility Boiling point Freezing point Melting Point magnetic Description Amount of space an object takes up D=m/v Ability to Dissolve At 1 atmosphere water boils at: 100 o C 212 Fahrenheit 373 K 0 o C or 32 Fahrenheit Point at which a solid becomes a liquid

ductility Physical Property malleability viscosity Description Metal can be pulled into a wire Metal can be pressed or hammered into sheets Thickness of a liquid Ex. Water vs syrup

Chromatography Chromatography is a method for separating substances in some mixtures.

• Different substances of the mixture have different solubility rates.

• If the substance is very soluble, it moves up the paper quickly.

• If the substance is less soluble, it creeps along very slowly.

Physical Changes • Observe some examples.

• What about solutions, mixtures and phase changes?

– They are examples of physical changes.

Mixture • A mixture is made of two or more substances that come together, but DO NOT CHEMICALLY combine.

• • Homogenous mixtures: are evenly mixed – Like tea or Koolaide Heterogeneous mixtures: are unevenly mixed – Like a pizza or salad

Solution • • • • • • A solution is a mixture in which the different particles are tiny and are mixed completely evenly EXAMPLES: Solid dissolved in liquid (sugar in water) Liquids dissolved in other liquids (water in alcohol) Gas dissolved in a gas (oxygen dissolved in the nitrogen in the air) Gas dissolved in a liquid (carbonated drink)

Soluble

• The ability to be dissolved.

What determines solubility?

• The temperature and the amount of the solvent

What is the difference between solute and solvent • • Solute: The dissolved substance in a solution.

( sugar and tea dissolved in water) • • Solvent: The dissolving agent in the solution, usually a liquid such as water.

( Water is considered the universal solvent)

Precipitate • As the solution cools, the solute will fall out of the mixture.

• How is this similar to weather precipitation?

Saturated • This is when no more solvent can be dissolved in the solution

Chemical Properties • Properties that do change the chemical nature of matter.

Chemical Property Ability to burn Ability to react with oxygen pH Description

Acids and Bases: pH • http://www.composiclean.com/sitebuildercon tent/sitebuilderpictures/phscaleWeb.jpg

Chemical Changes • Observe some examples of chemical changes • Hints that indicate a chemical change has taken place: change in temperature, color change, giving off gas – bubbles

Physical Change Torn paper – change in shape or size State of matter change Dissolved substances mixtures burning Chemical Change baking rusting Reacting chemically SIGNS OF CHEMICAL CHANGE: Odor, color change, fizzing bubbles, temperature change

Compound • • • Compounds can only be broken down by chemical means They have a fixed ratio or proportion of atoms An example is water