Chapter 6: Energy

Section 3: Chemical Energy

Notebooks – Title and Date

• Atoms are the smallest particle of matter

• Atoms can form molecules

• Molecules will form matter

• What is matter?

Anything that has mass and takes up space

Atoms form molecules

Two atoms of Hydrogen and one of

Oxygen form a water molecule

• https://www.youtube.com/watch?v=hc0E

tPPpZUU

• Atoms and Molecules - Chemistry For

Kids | Mocomi Kids

**Atoms forming

molecules are

united by bonds.

Chemical Energy

is energy stored in

the bonds between

atoms.

When bonds are

broken, energy is

released

** In our lives, there are chemical bonds

being created and destroyed

constantly, releasing or absorbing

chemical energy that can be used for

different purposes.

1) What is a chemical reaction?

**a process in which one or more substances are changed into others.

In a chemical reaction molecules or compounds are broken down and new ones are formed.

1) What is a chemical reaction?

• Reactants – hydrogen and oxygen

• Products –water (what is being formed)

2)Explain how energy and chemical bonds are

related.

What type of energy you find in chemical bonds,

kinetic or potential?

Two atoms are united by a

chemical bond.

There is chemical energy

stored in the bonds

between atoms.

chemical energy is a type

of potential energy

3) Explain what happens to the energy in our muscles.

• When you eat, the food provides chemical energy that will remain stored in your body.

• This energy will be used by your cells to perform many different functions

• The muscles in your body transform some of this chemical energy into kinetic energy and heat when they move.

• This is an example of energy transformation

4)What are endothermic and exothermic

reactions?

A chemical reaction that absorbs heat is called an endothermic reaction.

A chemical reaction that releases heat is called an exothermic reaction.

35) Explain Photosynthesis and

why

photosynthesis one of the most

important endothermic

chemical reactions on Earth?

**Photosynthesis

• Sunlight ( radiant or light energy) strikes the leaves

of plants

• Chemical reactions will occur with carbon

dioxide and water, in the presence of light, and

oxygen and sugar molecules ( food) will be

formed

• During this process the radiant energy in the

sunlight was transformed into chemical energy in

the sugar.

• the sugar is food for all living organisms

This is an example of energy transformation

• Photosynthesis is an

endothermic reaction, because

absorbs heat from the sun.

What is Rate of Reaction ?

• Rate of reaction is how fast or how slow a chemical reaction happens.

• Chemical reactions can occur at different rates.

What are the two ways to change the rate

(speed) of a chemical reaction?

• Adding a catalyst or changing the

temperature

• When you raise the temperature you

accelerate a chemical reaction

2) Catalyst

• A catalyst is a substance that changes the rate of a chemical reaction without any permanent change to its own structure.

• The catalyst doesn’t participate in the chemical reaction