7.2.2-Matter and Its Changes

Physical and Chemical Changes

Feb. 1st-5th

Multiple Choice

Warm up. Look at the image, and calculate which formula contains the most atoms of Oxygen

• 1

• 2

• 3

• 4

Physical Changes (Term)

• Are easily reversible, have no new products, and are often just a change of state of matter (Definition)

• Examples include:

• Solid to liquid

• Liquid to gas

• Gas to liquid

• Liquid to solid

Chemical Changes (Term)

• Are not easily reversed, new products are formed, reactants are used up, have evidence of heat/light/sound/fizzling occur, can produce electricity, or have a precipitate form (Definition)

• Example: Wood Burning

Multiple Choice

Is ice melting a physical or chemical change?

• Chemical

• Physical

Multiple Choice

Is frying an egg a chemical or physical change

• Chemical

• Physical

Reactants (Term)

• The substances in a chemical reaction that chemically combine

• Examples would be the combination of sodium and chlorine

Products (Term)

• The new substance made after a chemical reaction

• Examples include Salt (NaCl) after sodium and chlorine combine

Precipitates (Term)

• A solid that forms after two liquids chemically react (definition)

• Examples would include the combination of milk and vinegar

Multiple Choice

When two hydrogens chemically combine with one oxygen would what would water be?

• Reactant

• Product

• Precipitate

Evidence of a chemical change

• Abbreviation to remember = City, Girls, Like, To, Order, Pizza

• C: color change

• G: Gas

• L: Light is produced

• T: Temperature change

• O: odor is produced

• P: Precipitate is formed

Multiple Choice

What does the o stand for in the acronym that we learned?

• Gas

• Light

• Odor

• Osmosis

Open Ended

Give Examples of a Physical Change

Open Ended

Give Examples of a Chemical Change

Open Ended

Dr. Garret Sho takes a piece of notebook paper from her desk. As a demonstration she tears the paper into 14 pieces.

After Dr. Sho tears the paper, what would you expect to happen to the mass of the torn pieces?

Draw

Draw an example of a Physical and Chemical Change

Multiple Choice

What is the Mass of CO2? Hint think about the Law of Conservation of Mass.

• 12.0g

• 6.2g

• 46.2g

• 20.0g

Multiple Choice

Review the information in the graph. Which of these statements is true?

• The change from ice of liquid water is a chemical change.

• The change from liquid water to water vapor is a physical change.

• It takes the same amount of time for ice to melt as it does for liquid water to become water vapor.

• The change from ice to liquid water to water vapor shows a decrease in mass due to the changes in states of matter.

Multiple Choice

There are characteristics that differentiate a chemical change from a physical change.  Which statement describes a physical change?

• Iron combines with oxygen to form rust

• Lead is heated and becomes melts into a viscous liquid.

• Sodium metal reacts explosively with oxygen

• Calcium is added to acid and hydrogen gas is produced

Multiple Choice

Review the information in the graph. Which of these statements is true?

• The change from ice of liquid water is a chemical change.

• The change from liquid water to water vapor is a physical change.

• It takes the same amount of time for ice to melt as it does for liquid water to become water vapor.

• The change from ice to liquid water to water vapor shows a decrease in mass due to the changes in states of matter.

Poll

Did this help you today?

• Yes

• No

​Physical Change Definition:

​Change that does NOT result in a new substance.

​

​NO new substance formed

​

​CAN be easily reversed

​

​Temporary change

Multiple Choice

No new substance is formed in a physical change.

• True

• False

Multiple Choice

Evidence of a physical change.

• New substance
• Shape Change
• Light produced
• Gas released.

Multiple Choice

Chemical channges are ______________ chnages.

• Temporary

• Permanent

Multiple Choice

If a new substance is formed would this be a physical or chemical change?

• Physical
• Chemical

Multiple Choice

What kind of change is breaking a window?

Multiple Choice

Is sour milk a physical or chemical change?

• Physical
• Chemical

Multiple Choice

Is melting iron a physical or chemical change?

• Physical
• Chemical

Multiple Choice

Is digesting your food a physical or chemical change?

• Physical
• Chemical

Multiple Choice

Fireworks Exploding are a ________ change.

• Physical Change
• Chemical Change

Multiple Choice

What kind of change is baking a cake?

Multiple Choice

What kind of change is crushing a soda can?

Mixtures

is a type of matter that

1 ....... is composed of 2 or more substances that are physically combined

2...... has composition that can change (vary) from one sample to another

3....... can be physically separated into its components

4....... retains the properties of the individual components

Examples of mixture

NaCl (aq) ........ salt water

C6H12O6 (aq) ....... sugar solution

HCl (aq) ......... Hydrochloric acid solution

soil, concrete and air are also mixture

Homogeneous mixture

• the components of the mixture are uniformly and evenly mixed throughout

• sample taken with the same mixture have the same composition

Heterogeneous mixtures

• the components of the mixture are not uniformy mixed throughout

• sample taken with the sample mixture have different composition

Multiple Choice

Which is a mixture of substances?

• Cl_2(g)

• H₂O_(l)

• MgCl_2(s)

• KNO_3(aq)

Multiple Choice

Which is true of a KCl solution?

• It is composed of substances that are chemically combined.

• It is composed of substances that are physically combined.

• It is composed of substances with the same atomic number.

• It is a pure substance.

Multiple Choice

Which are elements?

• A

• B

• C & D

• C

Multiple Choice

When NaNO_3(s) is dissolved in water, the resulting solution is classified as a

• heterogenous compound

• homogeneous compound

• heterogeneous mixture

• homogeneous mixture

Multiple Choice

One similarity between all mixtures and compounds is that both

• are heterogeneous

• are homogeneous

• combine in definite ratio

• consist of two or more substances

Multiple Choice

Which phase allows molecules to move around each other?

• Solid

• Liquid

• Gas

• None of the above.

Movement of Molecules

Solid- molecules move in place

Liquid- molecules move around each other

Gas- molecules move away from each other

Multiple Choice

Why does your hand feel cold as an ice cube melts on it?

• Thermal energy is transferred from the ice to your hand

• Thermal energy can't transfer between your hand and ice

• Thermal energy is transferred from your hand to the ice

• Cold energy is transferred from the ice to your hand

Multiple Choice

Ralph and Sheila are at a construction site and they are stacking bricks. The diagram below shows the bricks before they touch. Use the information in the diagram to answer the question. After the bricks have been touching for a while, whose ​top brick will be cooler?

• Both will be the same temperature, because both bottom bricks transferred the same amount of energy.

• Sheila's top brick was will be cooler, because the energy that transferred to Sheila's top brick was spread out with more molecules.

• Ralph's top brick was cooler, because less energy has to transfer to Ralph's top brick.

Multiple Choice

What energy transformation occurs when a crock pot is plugged into an outlet and then the control knob is turned "on"?

• thermal to electrical

• mechanical to thermal

• electrical to thermal

• electrical to sound

Multiple Choice

According to the Law of Conservation of Energy, energy cannot be _________ or ____________.

• destroyed, destroyed

• created, saved

• created, destroyed

• lost, found

Multiple Choice

Electrical Energy is transferred to _____ Energy.

• Thermal

• Solar

• Electrical

• None

Multiple Choice

A hairdryer converts --

• electrical energy into chemical

• electrical energy into thermal

• chemical energy into mechanical

• thermal energy into mechanical

Multiple Choice

Which type of energy transformation occurs when a flashlight shines?

• chemical → thermal → electrical

• chemical → electrical → light

• thermal → chemical → light

• chemical → electrical → chemical

Multiple Choice

If a Lion ate a gazelle what kind of energy is being transferred?

• Mechanical

• Chemical

• Electrical

• Thermal

Multiple Choice

Which kind of energy change occurs when a candle is burning?

• Chemical to light.

• Light to electrical.

• Solar to heat.

• Chemical to electrical.

Multiple Choice

What energy transformation occurs when an alarm clock rings?

• electrical to mechanical, sound

• chemical to mechanical,sound

• electrical to thermal, chemical

• mechanical to mechanical, thermal, sound

• ​Living things VS. Objects​

• ​Living things:

• ​Eat, breathe, run, cry, get angry

• ​Do they have energy?

• ​Objects:

• ​Don't eat, don't breathe, don't move, don't cry, don't get angry.

​Let's remember...

Energy in Objects

​Did you know that all objects possess energy?

​

What is energy?

• It's everywhere around us and takes all sorts of forms.​

• ​How things change and move.

• ​It takes energy to cook food, to drive to school, and to jump in the air. Different forms of Energy

• ​"the ability to do work"

Multiple Choice

Choose TRUE OR FALSE: "We use energy to do everyday activities like eating, running, even sleeping"

• TRUE

• FALSE

Multiple Choice

CHOOSE TRUE OR FALSE: How we process energy is called WORK

• FALSE

• TRUE

​Kinetic Energy

• Pick up the bow and arrow and shoot it

• ​Stored energy = potential energy

• ​Transforms to moving/motion energy

• ​Also called "KINETIC"

Multiple Choice

What type of energy is this?

• Potential

• Kinetic

Multiple Choice

What type of energy is it?

• Potential

• Kinetic

Multiple Choice

The water falling is using what type of energy:

• Kinetic

• Potential

• None

• All of them

Law of Conservation of Mass

​Clear Learning Target:

​

​

I can define the Law of Conservation of Mass so that I can determine if examples given follow the rule.

​Elements and Compounds

https://www.youtube.com/watch?v=i2OE9ljBKD8

​Physical Change

• A Physical Change happens when a substance ​changes but no new substance is formed.

• ​Physical Change occurs when the state of a substance changes.

• Freezing

• Evaporating

​

​Examples include: Water Freezing, Cutting Paper, Melting Butter, Breaking Glass

​Chemical Change

​A Chemical Change Occurs when a new substance is formed.

​

​Indications that a new substance has formed (Chemical Change):

• A change in color

• Formation of Bubbles

• ​Temperature changes

• ​Forms a gas

​Examples of a Chemical Change: Wood burning, A nail rusting, Food Rotting.

Multiple Choice

Is this an example of a Physical or Chemical change? 

• Physical

• Chemical

Multiple Choice

Is this a image a physical or chemical change?

• Physical 

• Chemical

Multiple Choice

Is this image a physical or chemical change? 

• Physical 

• Chemical

​Law of Conservation of Mass

​Antoine Lavoisier - "Revolutionized Chemistry"

​

​

• ​Lavoisier discovered that "Mass can not be created or destroyed" by carefully measuring the product and reactants in many of the chemical reactions he was researching.

• ​Law of Conservation of Mass states that: "Mass can not be created or destroyed"

Products vs. Reactants

​RAP = Reactants Arrow Products

​

​

​

​

​

​

​

​Products and Reactants in a Chemical Equation

​

​Products and Reactants in a Chemical Reaction

​Reaction between Methane and Oxygen :

​

​All of the atoms that were present at the beginning of the reaction (reactants) are still present in the products. They have just been moved around or transformed!

​

Multiple Choice

What does the Law of Conservation of Mass state?

• Mass is created at the end of a chemical reaction

• Mass can not be created or destoryed 

• Mass is created in a physical change 

• New chemicals are formed when a chemical reaction takes place.

Counting The Atoms: Subscripts Vs. Coefficients

Multiple Choice

Using the picture, what is the coefficient of this chemical compound? 

• 3

• 4

• There isn't one 

Multiple Choice

Using the picture, what is the subscript of this chemical compound? 

• 4

• 3

• There isn't one

​​Counting Atoms Review

​

​Counting Atoms Review

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​​Counting Atoms Review

​

​Counting Atoms Review

​

Multiple Choice

What state of matter is represented in the picture above?

• solid

• liquid

• gas

Multiple Choice

What state of matter is represented in this picture?

• solid

• liquid

• gas

Multiple Choice

Heating a solid to a high temperature will usually result in this phase change.

• Condensation

• Melting

• Sublimation

• Evaporation

Multiple Choice

This state of matter expands to fill its container.

• Solid

• Liquid

• Gas

• Plasma

Multiple Choice

When an object has the ability to be stretched into a thin wire this is

• Density

• Ductility

• Dirtability

• Dissovility

Multiple Choice

The ability to hammered into a thin sheet or be bent is

• Ductility

• Solubility

• Density

• Malleability

Multiple Choice

which one is the definition of chemical property?

• a property or characteristic of a substance that is observed during a reaction where the chemical composition of a substance is changed
• any change that results in the formation of new chemical substances
• combustibility

Multiple Choice

Physical properties are

• properties that can be observed without changing the identity of the substance
• properties that describe how a substance changes into a completely different substance

Multiple Choice

Flammability (burns): Chemical or Physical Property

• Chemical Property
• Physical Property

Multiple Choice

Solubility (dissolves): Chemical or Physical Property

• Chemical Property
• Physical Property

Multiple Choice

Matter can not be created nor destroyed: it can only be

• Destroyed a little bit

• Invisible

• Transformed, changed

• None of the above

Multiple Choice

If reaction starts with 20g of reactants it should produce

• a total of 40g of products

• a total of 10g of products

• a total of 80 g of products

• a total of 20g of products

Multiple Choice

Mr. Brady did an experiment. The mass he started with was 15 grams. How much mass should he end with?

• less than 15 grams

• more than 15 grams

• 15 grams

Multiple Choice

What is the Law of Conservation of mass?

• Mass is created in a chemical reaction

• Mass is created in a physical change

• New chemicals formed from a chemical reaction have a larger overall mass than the original reactants

• Mass is never created or destroyed

Multiple Choice

Why do some substances float on water?

• they are warmer than water
• they are cooler than water
• they are more dense than water
• they are less dense than water

Multiple Choice

Which liquid is the least dense?

• oil
• water
• syrup 
• plastic bottle

Multiple Choice

What is the left part of a chemical equation called?
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

Multiple Choice

What is the right part of a chemical equation called...
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

Multiple Choice

Identify the Reactants in this equation.

• A

• B

Multiple Choice

A chemical reaction is balanced when

• both sides have the same elements
• Both sides have the same  number of atoms
• Same subscripts
• Same coefficients

Multiple Choice

The number in front of a compound or element is a 

• Subscript
• Coefficient
• Superscript
• Charge

Multiple Choice

The number to the lower side of an element is a 

• Subscript
• Superscript
• Coefficient
• Charge

Multiple Choice

Matter can not be created nor destroyed: it can only be

• Destroyed a little bit
• Invisible
• Transformed, changed
• None of the above

Multiple Choice

Is this balanced?
Al + O₂ → 2Al₂O₃

• Yes
• No

Multiple Choice

How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl₂ + H₂

• 1
• 2
• 3
• 4

Multiple Choice

Element or compound?
H₂O

• element
• compound

Multiple Choice

How many elements are in C₆H₁₂O₆?

• 1
• 2
• 3
• 4

Multiple Choice

What coefficient should be used to make the following equation balanced?

N₂+O₂--> _NO

• 1

• 2

• 3

• 4

Multiple Choice

What coefficient should be used to make the following equation balanced?
N₂+O₂--> _NO 

• 1
• 2
• 3
• 4