1. Matter, Forces, Energy, Motion and Heat
8th GRADE PHYSICS
Matter, Forces, Energy, Motion and Heat

2. READ TO STUDENTS: ALL MATTER IS COMPOSED OF ATOMS; THERE ARE OVER KNOWN 100 ELEMENTS THAT CAN BOND AND FORM COUNTLESS COMPOUNDS. REMEMBER: AN ATOM IS THE SMALLEST PART OF AN ELEMENT THAT STILL MAINTAINS ALL OF THE PROPERTIES 0F THAT ELEMENT
SECTION 1: MATTER

3. Important Terms
Chemistry- The study of the properties of matter and how matter changes.
Substance- A single kind of matter that is pure and has a specific set of properties.
Mixture-Two or more substances that are mixed together but not chemically combined.
Mixtures can be heterogeneous or homogeneous

4. DESCRIBING MATTER Question: What is matter?
Answer: Anything that has mass and takes up space
All matter is composed of atoms
Atom- The basic particle from which all elements are made
Element- A pure substance that cannot be broken down into other substances by chemical or physical means.

5. Chemical Bond- The force that holds two atoms together
Molecule- A particle made of two or more atoms bonded together
Compound- A pure substance made of two or more different elements chemically combined
chemical formula- A formula that gives the elements in a compound and the ratio of atoms
Example: H2O C6H4O2Fe5
IF THE RATIO OF THE ELEMENTS CHANGES THEN IT IS NO LONGER THAT COMPOUND. FOR EXAMPLE, WATER HAS A RATIO OF 2 HYDROGEN ATOMS FOR EVERY ONE OXYGEN ATOM. IF THE RATIO WAS CHANGED FROM 2:1 TO 3:1, YOU WOULD NO LONGER HAVE WATER

6. COMPOUNDS VS. MOLECULES
NOTE: ALL COMPOUNDS ARE MOLECULES BUT NOT ALL MOLECULES ARE COMPOUNDS

7. Matter has both physical and chemical properties

8. Properties of Matter Physical Property Examples
Chemical Property Examples
physical property- A characteristic of a pure substance that can be observed without changing it into another substance
Color
Size
Shape
Mass
Density
Volume
Texture
chemical property- A characteristic of a pure substance that describes its ability to change into a different substance
Reactivity
pH (is it an acid or a base)
Flammability
Toxicity
Oxidation states
Heat of combustion

9. MEASURING MATTER Tools of Measurement:
Mass: scale or triple beam balance
Length: ruler
Volume:
For a regular shaped object use the formula LxWxH
For a irregularly shaped object use water displacement
Density
D=M/V

10. Density of a regular shaped object
This block of wood has the following measurements
L= 10cm
W= 2cm
H= 5cm
Mass= 50 g
In your notebook, calculate the volume, then find the density. Remember to label the units
V= LxWxH V= 10x5x2= 100cm 3 D=M/V D=50/100= 0.5g/cm3

11. Density of an irregularly shaped object
Toy Dinosaur
Mass= 2mg
Volume= volume with object- volume without object
V=5.8mL-4.8mL= 1mL
What is the density or the toy dinosaur?
D=M/V
D=2mg/1mL = 2mg/mL
NOTE: 1mL=1cm3

12. CHANGES IN MATTER Matter can undergo physical and chemical changes
Physical Change- A change in a substance that does not change its identity
Examples: changing shape, form, state of matter
Chemical Change- A change in which one or more substances combine or break apart to form new substances
Examples: burning, oxidation, combustion, tarnishing, electrolysis

13. Chemical Changes

14. Physical Changes

15. ENERGY

16. ENERGY IN MATTER Key Terms:
Kinetic Energy- The energy of matter in motion
Potential Energy- The energy an object has because of its position; also the internal stored energy of an object, such as energy stored in chemical bonds

17. Forms of Energy
Chemical Energy- A form of potential energy that is stored in chemical bonds between atoms
Electromagnetic Energy- A form of energy that travels through space as waves
Electrical Energy- The energy of electrically charged particles moving from one place to another.

18. Energy Transformations

19. WORK

20. SPEED, ACCELERATION, and VELOCITY

21. THERMAL ENERGY (HEAT)