Energy Transfer Criterion C

The Law of Conservation of Energy states that energy cannot be created nor destroyed, but only changed from one form to another.

Multiple Choice

Energy cannot be ___________ or destroyed.

• used

• created

• recycled

A phase change graph is a temperature vs. time graph displaying the phases of matter and the temperature at which phase changes occur.

Multiple Choice

On this graph, as time increases, temperature...

• increases

• decreases

Multiple Choice

The diagonal lines on a phase change graph represent...

• states of matter

• phase change from one phase of matter to another

Multiple Choice

The flat lines on this graph represent

• phases of matter

• phase changes from one form of matter to another

As matter changes phase, thermal energy is absorbed or released until all particles of matter have changed. Therefore, the temperature remains constant.

Multiple Select

During phase change...

• temperature remains the same

• the matter is transforming from one form to another

• temperature increases

• energy is created

The melting point is the temperature at which a solid becomes a liquid.

The boiling point is the temperature at which a liquid becomes a gas.

The condensation point is the temperature at which a gas becomes a liquid.

 Condensation point = Boiling point

The freezing point is the temperature at which a liquid becomes a solid.

 Freezing point = Melting point

Heating and cooling systems regulate temperature by transferring energy.

A heating system is any device or process that transfers energy to a substance to raise its temperature.

 ex. Rubbing hands together, human       body, furnace, reptiles basking in       the sun, solar panels.

A cooling system is any device or process that transfers energy as heat out of a substance to lower its temperature.

 ex. Refrigerator, air conditioner,          condensation, sweating, heat             pumps.

Multiple Choice

Heating systems put heat INTO a system and cooling systems...

• take heat out

• put cold in

Physical Properties

A characteristic that can be observed or measured without changing the identity of the substance is called a physical property. Your senses can be used to detect properties like color, shape, size, texture, taste and odor among others. The way you described your favorite fruit was a list of it's physical properties.

Chemical Properties

A chemical property describes a property that is only observed when a substance changes into a new substance with different properties. Like when iron rusts and turns into a new substance called iron oxide.

Physical Changes

A physical change occurs when there is a change to one or more of the physical properties of a substance that does not result in the substance changing into something else.

Chemical changes

A chemical change occurs when one or more substances change into entirely new substances. In a chemical change, the chemical identity of a substance changes and a new substance is formed that has different properties.

Signs of a Chemical changes

Multiple Choice

Which phrase most accurately describes a chemical change?

• A change on the molecular level

• A change in appearance

• A change in taste

• A change in form

Multiple Choice

How are physical and chemical properties different?

• Chemical properties only apply to chemicals. Physical properties apply to everything.
• Chemical properties are only observable as the substance is changing. Physical properties are easily observed or measured.
• Chemical properties are easy to reverse, and physical properties cannot be reversed. 

Multiple Choice

Which answer makes the sentence true. 
Matter is anything that _______________________________. 

• is burned to make heat
• takes up space and has mass
• lets electricity move through it

Multiple Choice

Which type of property is the ability to conduct electricity?

• physical property
• chemical property

Multiple Choice

Which is NOT a physical property?

• odor
• reacts with acid
• ability to conduct electric current
• hardness

Multiple Choice

Which one of these is a chemical property?

• melting point
• boiling point
• color
• flammability

Multiple Choice

Photosynthesis is an example of a

• physical change
• chemical change

Multiple Choice

Photosynthesis is an example of a

• physical change
• chemical change

Multiple Choice

A solid piece of chocolate is melted and changed to liquid form. Which property of the piece of chocolate will remain the same?

• Texture
• Temperature
  
• Shape
•  Mass

Multiple Choice

Which of the following IS a clue that a chemical change has occurred? 

• State of matter change
• Size Change
• Change in temperature
• Shape change

Multiple Choice

Is mold growing on cheese a physical or chemical change?

• Physical 
• Chemical

Multiple Choice

Is milk going sour a physical or chemical change?

• Physical 
• Chemical

Multiple Choice

Is Gatorade powder dissolving in water physical or chemical change?

• Physical 
• Chemical

Multiple Choice

How does rust form?

• Through paint flaking off of a metal surface

• Through a chemical reaction between iron and oxygen

• Through weathering

• Through the physical mixing of iron and water

Multiple Choice

What is an example of a chemical change that happens inside your body?

• Food being broken down by enzymes in your stomach

• Food being broken into small pieces by your teeth

• Food being moved from your esophagus into your stomach

• Water being absorbed inside your large intestine

Multiple Choice

What does it mean when there is a physical change?

• Matter has changed from one substance into another.

• Matter has changed on the molecular level.

• A new substance has been formed.

• Matter has changed size, shape or form.

Multiple Choice

Which of the following is an example of a physical change?

• Water freezing into ice.

• A piece of wood burning.

• A toy car rusting.

• Zinc producing hydrogen gas when mixed with water.

Multiple Choice

If a sheet of paper has been folded into a paper airplane, what has happened to the paper?

• a chemical change

• a physical change

• a chemical property

• a physical property

Multiple Choice

What is happening when your body changes the food you eat into energy you need to grow?

• a chemical change

• a physical change

• a chemical property

• a physical property

Multiple Choice

Why does an increase in temperature result in an increase in reaction rate?

• An increase in temperature raises the activation energy which increases the reaction rate.

• An increase in temperature causes the molecules to increase in size which increases reaction rate

• An increase in temperature decreases the concentration of reactants which increases reaction rate.

• An increase in temperature causes an increases the number of collisions which increases reaction rates.

Multiple Choice

Energy + 6CO₂ + 6H₂O → 6O₂ + C₆H₁₂O₆

During photosynthesis, sugar C₆H₁₂O₆ is produced from carbon dioxide, water, and sunlight. Which statement BEST explains what happens during photosynthesis?

• Atoms are gained when sugar is formed

• Single atoms are converted into molecules

• Atoms from compounds are lost when sugar is formed

• Atoms of compounds are rearranged to form new compounds

​Activation Energy

​Activation energy is the minimum amount of energy needed to start a chemical reaction

• ​All chemical reactions need a certain amount of activation energy to get started

​

​For a reaction to start, activation energy must be added. An electric spark or adding of heat can provide that energy

​Exothermic Reactions

​This type of reaction results in a release of energy

​

​The burning of fuels, such as wood, natural gas, or oil, is an example of an exothermic reaction

​Endothermic Reaction

​This type of reaction must continually absorb energy to keep going

​

​Most endothermic reactions require continuous energy

• ​For example, cooking a hamburger requires adding energy constantly until the meat is done

Fill in the Blank

In order for reactions to get started, ____ energy needs to be added.

​What affects the rate of a chemical reaction?

​Chemical reactions don't all occur at the same rate.

• ​Explosions: fast

• ​Rusting of iron: slow

​

​Factors

1. ​Surface area

2. ​Temperature

3. ​Concentration

4. The presence of catalysts and inhibitors

​Surface Area

• ​When a piece of solid substance reacts with a liquid or gas, only the particles on the surface of the solid come into contact with the other reactant

• ​If you break the solid into smaller pieces, more particles are exposed to the surface and the reaction happens faster

• ​Example:

  • ​Chewing your food breaks it into smaller pieces that your body can digest more easily and quickly

​Temperature

• ​When you heat a substance, its particles move faster. Faster moving particles have more energy, which helps reactants get over the activation energy barrier more quickly

• ​In contrast, reducing the temperature slows down reaction rates

• ​Example:

  • ​You store milk and other foods in the refrigerator because keeping foods cold slows down those reactions, so your foods stay fresh longer

​Concentration

• ​Concentration is the amount of a substance in a given volume

  • ​Ex: Sugar added to tea- the more sugar you add, the sweeter it tastes because the concentration of sugar is greater

• ​Increasing the concentration of reactants supplies more particles to react

  • ​Ex: "elephant toothpaste"

​Catalysts

​A catalyst increases the reaction rate by lowering the activation energy needed

• ​The cells in your body contain thousands of biological catalysts called enzymes that help these reactions occur at body temperature

• ​Chemical reactions using enzymes require less activation energy and can happen at lower temperatures

​Inhibitors

​A material used to decrease the rate of a chemical reaction is an in inhibitor

​

• ​Inhibitors called preservatives are added to food to prevent spoiling

Multiple Choice

To slow down a reaction, you can ___ the concentration of the reactants.

• increase

• decrease

Multiple Choice

What would react more quickly in the air, a pile of grain or a cloud of grain dust?

• Pile of grain

• Grain dust

What is a property of matter?

Properties of matter are the characteristics that describe a substance or object. These properties are generally grouped into two categories: Physical or Chemical.

Poll

How do you think Clovis NM gets electricity that people can use in their homes?

• Wind Energy

• Coal energy

• Nuclear Energy

• Hydroelectric dams

How is electricity made?

There are many ways that depend on our geographical locations.

Multiple Choice

True or False: There are many different natural resources that are used to create electricity?

• True

• False

Multiple Select

Which of these is a source of energy? Choose all that apply.

• Coal

• Wind

• Biological wastes

• Water

• Nuclear energy

Multiple Select

What does it mean to say that "electricity is less centralized"?

• People commonly use a locations natural resources for energy.

• Electricity is closer to the consumers.

• More options exist for electricity.

• Electricity is in one main location.

Multiple Choice

Which of these is true?

• Voltage is lowered in steps for use in homes and businesses.

• Homes used very high voltage electricity.

• Voltage must be NOT lowered for use in common electronics.

Energy transfer

L 2.4

Objectives

• Understand how energy transfers are shown in diagrams

• Be able to construct energy transfer diagrams

Energy (Change, transfer, transform) diagrams

Energy transfer diagrams are a useful way of showing energy transfers.

diagram for a battery-powered radio.

 televisions or catapults. 

 Can you guess what the diagram is for? This is an energy transfer diagram for a human being

​

Ikenna is cycling along the road. He sees a small hill ahead. He stops pedalling when he gets to the hill. He freewheels up the hill, slowing down as he goes. He gets to the top of the hill and then freewheels down the other side, speeding up as he goes. 

​

Multiple Choice

The glow sticks produce light for a short amount of time. The light from the glow stick is a conversion from what to what?

• thermal to light
• gravitational to potential
• radiant to electrical
• chemical to light

Multiple Choice

Wind turbines and windmills convert what energy to another?

• Kinetic to electric
• Gravitational potential to electric
• Mechanical to potential
• Thermal to sound

Multiple Choice

On a roller coaster, where is maximum potential energy?

• At the bottom of a big hill
• When going around a corner
• When going upside down
• At the top of a big hill

Multiple Choice

What type of energy is in this picture?

• Kinetic
• Potential
• Chemical
• Sound

Multiple Choice

What form of energy transfer is most likely responsible when your clothes dryer dries your clothes?

• Potential to Chemical to Nuclear

• Kinetic to Thermal to Light

• Chemical to Mechanical to Electrical

• Electrical to kinetic to Thermal

Multiple Choice

What type of energy transfer is most likely responsible when a plant converts the suns energy into food?

• Chemical to Solar
• Solar to chemical
• Light to electrical
• Electrical to chemical

Multiple Choice

If you are playing sports, this type of energy is present when the ball is going the fastest.

• Electrical
• Potential
• Kinetic
• Chemical

Multiple Choice

A TV does not give off this type of energy.

• Light
• Thermal
• Sound
• Solar

Multiple Choice

What does a solar cell do?

• it converts light into electrical energy

• it converts wind into electrical energy

• it transmits radio wave signals into space

• it converts water into solar energy

Multiple Choice

What form of energy is also described as "energy of motion"?

• Potential
• Mechanical
• Kinetic
• Electrical

Multiple Choice

If your cup of hot chocolate is really hot that means it has a lot of this type of energy.

• Chemical
• Thermal
• Electrical
• Potential

Multiple Choice

"Stored energy" is another way of describing what energy type?

• Potential
• Electrical
• Kinetic
• Mechanical

Multiple Choice

This form of energy does NOT come from the sun.

• Solar
• Thermal
• Light
• Sound

Multiple Choice

You could find a lot this type of energy at the top of a tall tree.

• Electrical
• Kinetic
• Potential
• Mechanical