1. 10 Week Science Study Guide
Grade 8

2. 1. Lab safety rules Follow directions Never eat or drink in lab
Wear safety goggles
Don’t fool around in the lab
Ask if you are sure about something

3. 2. Steps of scientific method
State a problem
Gather information
State a hypothesis
Experiment
Data and results
conclusion

4. 3. Hypothesis
A logical guess or prediction about something in science (educated guess)

5. 4. Units of measurement Mass (grams) Volume of solid (cm3)
Volume of liquid (ml) or (liter)
Length of a cube (cm)
Distance from Whitesboro to NYC (km)

6. 5. Mass and weight
Mass is the amount of stuff in an object and it cannot change
Weight is the pull of gravity and can change

7. 6. MASS Amount of matter or stuff in an object
Measured with a triple beam balance
Grams

8. 7- 9 VOLUME Amount of space an object takes up
Measured with a graduated cylinder for liquid volumes
V = LxWxH using a ruler for
regular sided objects (cm3)

9. 10 - 11 Phases of matter Phase of matter Shape Volume solid No change
liquid
Changes
gas

10. 12. Phases of matter Phase change Includes these phases Evaporation
Liquid to gas
Freezing
Liquid to solid
Melting
Solid to liquid
Sublimation
Solid to gas
Condensation
Gas to liquid

11. 13 & 14 Phases of matter
Particles move fastest with a gas and slowest with a solid
When objects are heated the particles move fastest and when they get cooled down, particle motion slows down

12. 15. PERIODIC TABLE
Mendeleev – developed 1st periodic table of elements
Organized in order of atomic mass

13. 16. PERIODIC TABLE Horizontal Rows – called Periods There are 7
Elements have no common characteristics

14. 16. PERIODIC TABLE Vertical Columns – called groups or families
There are 18
Elements have common characteristics

15. 17. STRUCTURE OF THE ATOM NUCLEUS – center of the atom
Protons: positive
Neutrons: neutral
ELECTRON CLOUD – surrounds nucleus
Electrons: negative

16. 18. PERIODIC TABLE
Atomic Mass: protons plus neutrons (actual mass of element)
Atomic Number: tells number of protons or electrons

17. 19. Electron counts in each energy level
Level 1: 2 electrons
Level 2: 8 electrons
Level 3: 8 electrons
Level 4: 8 electrons

18. 20. Mass number
This number comes from the total proton and total neutrons found in the nucleus added together

19. 21. ISOTOPES
Atoms of the same element with different numbers of neutrons

20. 22,25,26,30. Families on periodic table
Can be determined by group number!
Group #1 = 1 valence electron (alkali metals) very reactive
Group #2 = 2 valence electrons (alkaline metals)
Group #3-12 = 3 valence electrons (transition metals)
Group # 13 = 3 valence electrons (boron )
Group # 14 = 4 valence electrons (carbon)
Group #15 = 5 valence electrons (nitrogen)
Group # 16 = 6 valence electrons (oxygen)
Group # 17 = 7 valence electrons (halogens) very reactive
Group #18 = 8 valence electrons (noble gases) not reactive

21. 23 & 24THE ZIG-ZAG LINE LEFT = metals RIGHT = nonmetals
Malleable – can be formed into thin sheets
Ductile – can be formed into wires
Have luster
Conducts electricity and heat
RIGHT = nonmetals
Brittle
Dull
Nonconductors of heat and electricity

22. 27 – 29 DENSITY Amount of mass in a given volume D = m/V
Density of water is 1.0 g/mL
Objects float if they are less dense than water
Density never changes unless you change the material