1. 6th Grade Life Science Miss Sauer
PHYSICAL & CHEMICAL CHANGES
6th Grade Life Science
Miss Sauer

2. VIDEOS Physical & Chemical Changes Videos:
(24:43 The Magic School Bus: Gets Ready, Set, Dough)

3. VIDEOS Physical & Chemical Changes Videos:
(11:08)
(6:25) (Have students write list and predict if it’s a physical or chemical property)

4. Chapter 15 - PHYSICAL & CHEMICAL CHANGES
Main Idea: Energy can cause physical changes in matter. It is needed to change volume, temperature, or pressure of matter.

5. PHYSICAL CHANGES: Physical Change: Changes in shape, size, or state.
During a physical change, a substance does not become a different substance. Its chemical make-up stays the same.

6. PHYSICAL CHANGES:
During physical changes that involve heating/cooling, the motion of particles changes. The energy associated with motion is called kinetic energy. The faster the particles move in an object, the higher the object’s kinetic energy.

7. PHYSICAL CHANGES: (Kinetic Energy – Using energy)
(Potential Energy – storing energy)

8. PHYSICAL CHANGES:
Temperature: describes the average kinetic energy of its particles. This can be measured with a thermometer.

9. PHYSICAL CHANGES:
Thermal Energy: Total kinetic energy of the particles of a sample. Relates to the temperature and amount of the sample.
A sample with a greater mass has more particles and will have more thermal energy.
More mass - hotter
Less mass - colder

10. PHYSICAL CHANGES:
Thermal Expansion: increase in size due to increase in temperature.

11. PHYSICAL CHANGES:
Volume: is the amount of space that a substance fills.
Liquids have a greater thermal expansion than solids.
Gases have a still greater thermal expansion.
Solids – Liquids – Gases
(from least to greatest thermal expansion)

12. PHYSICAL CHANGES:
Pressure: is the amount of force exerted per unit area.
As temperature increases, particles move more quickly, & and pressure increases.
As temperature decreases, kinetic energy of gas particles decreases, move more slowly, and the volume/pressure decreases.

13. PHYSICAL CHANGES:

14. PHYSICAL CHANGES:
As temperature decreases, kinetic energy of gas particles decreases, move more slowly, and the volume/pressure decreases.
As temperature increases, particles move more quickly, & and pressure increases.

15. PHYSICAL CHANGES:
If the air pressure inside a container is less than the air pressure outside the container, the container will: crumple
If the air pressure inside a container is more than the air pressure outside the container, the container will: expand

16. PHYSICAL CHANGES:
If the air pressure inside
outside

17. PHYSICAL CHANGES:

18. PHYSICAL CHANGES: https://www.youtube.com/watch?v=fxLY1SGXV_E
Peeps expanding and shrinking (4:35)

20. Energy and Chemical Change:
Main Idea: A chemical change involves making and breaking chemical bonds to form new substances. Chemical changes can either absorb or release energy.

21. Energy and Chemical Change:
Chemical Change: a change of a substance to FORM A NEW SUBSTANCE.
Examples of Chemical Changes: Color change (rust on your bike; bananas ripening), fizzing or foaming (vinegar & baking soda).

22. Energy and Chemical Change:
Many chemical changes are rapid and give off large amounts of light and heat. All burning is an example of a chemical change.

23. Energy and Chemical Change:
When gasoline in a car engine burns, the chemical change provides energy to make the car run.
Other chemical changes can happen more slowly, such as, changes in your body as you get older or life cycles.

24. Energy and Chemical Change:
Chemical changes involve the breaking of existing bonds and forming new bonds. Both of these actions involve energy. When bonds break, energy is absorbed from the environment. When bonds form, energy is released.

25. Energy and Chemical Change:
The substances that form during a chemical change usually have different physical and chemical properties from the original substances. That’s because the new substances have a different chemical makeup.

26. Energy and Chemical Change:

27. Energy and Chemical Change:
Chemical Reaction: the formation of one or more new substances with properties and chemical compositions that differ from the original substances. All chemical changes involve chemical reactions.

28. Energy and Chemical Change:
Exothermic Reaction: a reaction in which energy is released.
Exothermic reactions can give off energy in the form of light, heat, or even sound.
*EXO – sounds like EXIT*

29. Energy and Chemical Change:
Examples of Exothermic Reactions: most cases involving burning (fireworks – chemical reactions in the burning fireworks produce light and sound); many chemical reactions that take place in your body (respiration-breakdown of sugar glucose from food in the presence of oxygen, carbon dioxide and water are formed, the energy released during respiration is used to make your body function).

30. Energy and Chemical Change:
Endothermic Reaction: a reaction in which energy is absorbed.

31. Energy and Chemical Change:
Energy is released / Energy is absorbed
making ice cubes
melting ice cubes
formation of snow in clouds
conversion of frost to water vapor
condensation of rain from water vapor
evaporation of water
a candle flame
forming a cation from an atom in the gas phase
mixing sodium sulfite and bleach
baking bread
rusting iron
cooking an egg
burning sugar
producing sugar by photosynthesis
forming ion pairs
separating ion pairs
Combining atoms to make a molecule in the gas phase
splitting a gas molecule apart

32. Energy and Chemical Change:
Energy is released / Energy is absorbed
mixing water and strong acids
mixing water and ammonium nitrate
mixing water with an anhydrous salt
making an anhydrous salt from a hydrate
crystallizing liquid salts (as in sodium acetate in chemical handwarmers)
melting solid salts
nuclear fission
reaction of barium hydroxide octahydrate crystals with dry ammonium chloride
mixing water with calcium chloride
reaction of thionyl chloride (SOCl2) with cobalt(II) sulfate heptahydrate

33. Energy and Chemical Change:
Chemical Equation: a way of showing the chemical formulas and symbols of the substances that react and form in a chemical reaction.

34. Energy and Chemical Change:
Chemical Reactions can be classified according to whether they release or absorb energy. They can also be classified according to the way the atoms of the reacting substances group together or come apart (synthesis, decomposition, single-replacement, double-replacement or combustion reactions).

35. Energy and Chemical Change:
Synthesis: Two substances react to form a single substance. Only one product forms.

36. Energy and Chemical Change:
Decomposition: A single substance breaks down to form two or more substances.

37. Energy and Chemical Change:
Decomposition:

38. Energy and Chemical Change:
Single-Replacement: When one element replaces another element in a compound.
Pure elements will be on both sides of the equation.

39. Energy and Chemical Change:
Double-Replacement: Two atoms or groups of atoms switch places.

40. Energy and Chemical Change:
Combustion: A compound reacts with oxygen to form water, often releasing a great amount of energy. Combustion is always an exothermic reaction.

41. Energy and Chemical Change:
Law of Conservation of Matter: matter cannot be created or destroyed.
For example, in any chemical reaction, the total mass of the substance does not change, no matter what new products form or how different the properties of the new substance are.

42. Energy and Chemical Change:

43. VIDEOS
(6:52 Types of Chemical Reactions)
Demos:
(4:58 SINGLE REPLACEMENT CHEMICAL REACTION AND SYNTHESIS REACTION)
(7:22 DOUBLE REPLACEMENT CHEMICAL REACTION LAB DEMONSTRATION)

44. Closure Questions What is potential energy? What is kinetic energy?
What is temperature?
During a physical change, does a substance become a different substance? Does its chemical make-up stay the same?
During a chemical change, does a substance become a different substance? Does its chemical make-up stay the same?
What is thermal energy?
What is thermal expansion?

45. Closure Questions What is pressure?
As temperature decreases, does the kinetic energy of gas particles increase or decrease, and does the volume/pressure increase or decrease?
As temperature increases, do particles move slowly or quickly, & and does pressure decrease or increase?

46. Closure Questions
If the air pressure inside a container is less than the air pressure outside the container, the container will: ____________?
If the air pressure inside a container is more than the air pressure outside the container, the container will: ____________?
What is a chemical reaction?
What is the difference between an exothermic and endothermic reaction?

47. Closure Questions
Provide an example of an exothermic and an endothermic reaction?
What is a chemical equation?
What is synthesis?
What is decomposition?
What is single replacement?
What is double replacement?
What is combustion?
What is the law of conservation?