It Was Here Just a Moment Ago!

It Was Here Just a Moment Ago!

STAAR Category 1Matter and EnergySTAAR Category 1Matter and Energy

•TEKS (8.5) The student knows that matter is composed of atoms and has chemical and physical properties. The student is expected to:

• (E) investigate how evidence of chemical reactions indicate that new substances with different properties are formed; and

Learning ObjectivesLearning Objectives

• 1.  The student will demonstrate chemical change as evidenced by a change in color.

• 2.  The student will measure temperature change as the result of a chemical reaction.

• 3.  The student will demonstrate a chemical reaction that produces gases.

• 4. The student will demonstrate a chemical change that results in the formation of a precipitate.

• 5. The student will use models to explain chemical formulas.

ENGAGEENGAGE

•Balloon Gas–What happened?

Physical vs Chemical Change

Physical Changes

Alter the size &/or shape

Cut, grind, dissolve

Phase Changes

Physical ChangesPhysical Changes

Physical Changes

Easily changed back to original form

Chemical Changes•New stuff is made

•Cannot change new stuff back into original form easily

•Chemical composition of new substance is different from original

Raw ChickenRaw Chicken Cooked Cooked ChickenChicken

Physical or Chemical?Physical or Chemical?Write your explanation on page 7 of your Write your explanation on page 7 of your

IANIAN

Bellringer 10/14/2014- You must complete to do the

lab!

5 Evidences of Chemical Change1.Precipitate (2 clears make a

cloudy)2.Energy change (hot, cold, light,

sound, electricity, etc.)3.(Unexpected) Color Change4.Bubbles, fizzing, gas produced5.Smell Change

How to remember

• Please= Precipitate• Excuse = energy change• Burps = bubbles• Coughs = color change • Sneezes = smell change

#1 Precipitate

Two clear solutions make a cloudy solution

#2 Energy Change

As candle was burns, it gives off heat and light

#3 Color Change (Unexpected)

Colorless methane burns blue

#4 Bubbles or Fizzing

Alka Seltzer in Alka Seltzer in water makes water makes

carbon dioxide carbon dioxide gasgas

#5 Smell Change

Baked cupcakes smell differently Baked cupcakes smell differently than batterthan batter

Physical or Chemical?

You decide. . .

How do you know?How do you know?

Physical or Chemical?

You decide. . .

How do you know?How do you know?

Physical or Chemical?

You decide. . .

How do you know?How do you know?

Chemical Changes Foldable

•Chemical Changes Foldable- Glue to page 41

•Page 42: title- –“Chemical Changes Mini Labs 1 and 2”

•Page 43: title- –“Chemical Changes Mini Labs 3 and 4”

Mini Lab #1

• Materials: 15 mL of acetic acid, spoonful of sodium bicarbonate

• Prediction “I think ___________will happen when I mix acetic acid and sodium bicarbonate together.”

• Results:

Mini Lab #1

1. Use the graduated cylinder to add 15 milliliters of acetic acid to the baggie containing sodium bicarbonate. Close it tightly.

2. Observe the baggie with your eyes and hands as the change takes place.

3. Record evidence of a chemical change on your sheet.

Results

• A chemical change (did/did not) occur because ______________happened

Mini Lab #2

• Materials: 20 mL of water, 1/2 spoonful of sodium bicarbonate, 2 spoonfuls of calcium chloride

• Prediction: I think ____________ will happen when I mix water, sodium bicarbonate, and calcium chloride together.

Mini Lab #2

1. Mix a spoonful of sodium bicarbonate and a spoonful of calcium chloride together inside a plastic bag.

2. Use the graduated cylinder to add 15 ml of acetic acid to the bag. Close it quickly!

3. Observe the baggie with your eyes and hands as the change takes place.

4. Record evidence of a chemical change on your sheet.

Mini Lab #3

• Materials: 10 mL of acetic acid, 5 drops of universal indicator

• Prediction: “I think ____________will happen when I mix acetic acid and universal indicator together.”

Mini Lab #3

1. Add 10 ml of acetic acid to a graduated cylinder.

2. Pour the acetic acid into the small beaker.

3. Add 1 dropper of universal indicator or cabbage juice to the beaker.

4. Observe the beaker with your eyes and as the change takes place.

5. Record evidence of a chemical change on page 42 of your IAN.

EXPLOREEXPLORE

• Red Light – Green Light• For the Rust of My Life• Take a Powder• Clabbered Clumps• Witches Brew• Bubble, Bubble, Toil & Trouble• It’s All Aglow• Chemical Sunshine

– Please- Precipitate (2 clears make cloudy)

– Excuse- Energy change (heat, light, sound, electricity)

– Coughs- Color change (unexpected)– Sneezes- Smell Change– Burps- Bubbles or fizzing (gas

produced)

Evidence of Chemical Change

EXPLAINEXPLAIN

• Every reaction we did shows evidence of chemical change- what are 5?– Please- Precipitate (2 clears make cloudy)– Excuse- Energy change (heat, light, sound,

electricity)

– Coughs- Color change (unexpected)– Sneezes- Smell Change– Burps- Bubbles or fizzing (gas

produced)

ELABORATEELABORATE

• Mixing it Up• Irreversible Consequences

Bellringer 10/20/2014- pg 7 or 8

•What is a precipitate?

Homework

• Study for your vocabulary quiz (summative)!!! Quiz is on Wednesday!!!!

• Words: subscript, coefficient, chemical formula, alkali metal, noble gas, metal, nonmetal, metalloid, group, period, atom, proton, neutron, electron, valence electron

Classwork

• Atoms Retest (front of the room): Watch the Atomic model brainpop and complete the quiz

• Lab (back of the room): follow the lab directions for mini lab #6. If you complete you can finish any mini lab that you did not complete.

True or False

Chemicals are only found in chem labs

Fabulous Fact or Mystical Myth

Fabulous Fact or Mystical Myth

Chemistry runs everyone and everything!

True or False

Physical and chemical changes never happen at the same

True or False

Energy changes during a chemical reaction

always give off heat

Energy changes during chemical reactions can give off heat and get hotter, absorb heat and get colder, give off light, sound, and electricity, etc.

EVALUATEEVALUATE

•How many atoms of copper in 2 molecules Cu2O?

•What happens to atoms in chemical reactions?

•What physical properties can change in a chemical reaction?