Study Materials Good Luck! Rock on!
Scientific Knowledge and Inquiry: Scientific Investigation What you need to know. A. Scientific Method 1. Independent variable = manipulated variable 2. dependent variable = responding variable 3. controlled variable 4. Control group
Check out this Scientific Experiment • http://step.nn.k12.va.us/science/6th_science/ppt/Scientific_Method.ppt#28
Observation and Inference • Observation = senses • Can you see, touch, smell, feel, or hear it? • Inference = come to a conclusion about the observation.
Ohh… This liquid is green and it is leaking from a brown can. I also smell it. Observation Observation: when studying something describe only facts that you can see, touch, smell and hear. You are not making any guesses. THIS IS NOT AN OPINION!!
Based on my observations, I think that this can is old and is leaking a toxic substance. Inference Inference: using your observations to make a guess about an object or an outcome THIS CAN BE A SCIENTIFIC OPINION
Earth Structure • Crust • Rocky outer layer • Mantle • Thick layer of hot but solid rock • Core • Outer core of melted metal • Inner core = solid chunk of Iron
Plate tectonics • Theory of Plate tectonics • Pieces of earth, called plates, move about the earth. • Check this site out • http://emvc.geol.ucsb.edu/animations/flash/pangea.swf
Continental Drift • Alfred Wegener (1880-1930) • Hypothesized that continents were once joined together in a supercontinent • Pangea • Fossils of the same animals were found on the coasts of South America, Africa, and the Northern tip of Antarctica
Sea Floor Spreading • Process which new sea floor is created at mid-oceanic ridges. • Sea floor spreads apart and magma rises . • Water cools the magma, creating a new sea floor
Plate Boundaries • Outer earth sits on 12 plates. • At each plate there is a boundary • 3 kinds of boundaries • Divergent • Convergent • Transform
Divergent Boundary • When plates move away from each other.
Convergent Boundary • Plates come together or collide. • One plate goes under (subduction) another plate • Mountain Building • Rocky Mountains
Transform Boundary • Plates slide past each other in opposite directions • EARTHQUAKES • California San Andreas Fault
This shows all the boundaries at the same time. • http://www.classzone.com/books/earth_science/terc/content/visualizations/es0804/es0804page01.cfm?chapter_no=visualization
Relative dating • Fossils are the age of the rock they are found in. • Older fossils on the bottom. • Younger fossils on top.
Stars Basic Info • Give off massive amounts of energy • Hottest stars appear BLUE • Next hottest appear RED • Coolest stars appear Yellow • You can tell the surface temperature of a star with the naked eye.
Basic Info cont. • Brightest Stars are closest • Dim stars are farther away. • No direct way of finding exact mass of stars.
How Stars Produce Energy • Nuclear Fusion • Hydrogen nuclei fuse together to for Helium atoms
Geocentric Theory • A model of the solar system where stars and planets revolve around Earth. • Developed by ancient Greeks. • A.D. 140 • NOT HOW THINGS ARE!!!
Heliocentric Model • Earth and Planets revolve around sun.
Rolling friction – opposite force that acts on a rolling object. 1. 100 to 1000 times less than static or sliding friction. • Fluid friction – friction that acts on an object in water or air. L. Gravity – acts downward to the center of the earth. 1. Gravity causes objects to accelerate downward. M. Push force – force makes you go forward
An object in motion wants to stay in motion. An object at rest wants to stay at rest. • Describe Newton’s 1st Law in Your Own Words. INERTIA
When something changes speed or direction it accelerates. • Describe Newtons 2nd Law.
For every action there’s an equal and opposite reaction. • Describe Newton’s 3rd Law. Guy jumps forward, boat goes backward.
Physical Property • Any characteristic of a material that can be observed without changing the composition of the material. • 1. Viscosity– The tendency of a liquid to quit flowing or its resistance to flowing.
1. Viscosity– The tendency of a liquid to quit flowing or its resistance to flowing. • High viscosity = the slower it moves • Syrup has a higher viscosity than water http://plc.cwru.edu/tutorial/enhanced/lab/visco/intro/intro.htm
2. Malleability– The ability of a solid to be hammered without shattering • Metals are usually malleable. If not, we wouldn’t have gold jewelry or knives! • Other materials break /shatter when hammered
3.Density– Ratio of an object’s mass to volume: Mass/volume (memorize formula!) • Denser object’s sink and less dense objects float • The box that has more balls has more mass per unit of volume. This property of matter is called density.
4. Hardness– A material’s ability to resist scratching • Glass is harder than a penny so glass can scratch a penny
5. Ductility - The ability of a substance to be stretched; the ability for a metal to be drawn into wire.
Conductivity • The ability to allow electricity/heat to flow. • The more conductivity = the more room electrons have to move. • Was a test question a couple of years ago……
Dull metal Shiny black Shiny metal Dull black Emission experiment Four containers were filled with warm water. Which container would have the warmest water after ten minutes? shiny metal The __________ container would be the warmest after ten minutes because its shiny surface reflects heat _______ back into the container so less is lost. The ________ container would be the coolest because it is the best at _______ heat radiation. radiation dull black emitting
Protons = Positive part of nucleus • 1. found in nucleus • 2. can tell you the exact element • Example: if you know the element has 10 protons; you just find element 10 on the periodic table • Used to find atomic weight
Neutrons = no charge • Used to find atomic mass • Sometimes the same element can have different numbers of neutrons = ISOTOPES • Ex. Carbon 12 has 6 neutrons; 6 protons • Carbon 14 has 8 neutrons; 6 protons • Proton number NEVER changes
Electrons = negative • Atomic number = # of electrons • Found outside the nucleus • Weight almost nothing • Number of electrons plays no role in calculating the weight of atoms.
Valence Electrons • Electrons found in the outershell
Dot Diagrams • Tell you number of valence electrons • Chlorine has 7 valence electrons because it has 7 dots around it
Families • Each column is called a family. • Every family has similar characteristics • The biggest characteristic is valence electrons • The number of valence electrons is represented by Roman numerals above the columns • Noble gas have 8 valence electrons even though it has an 0
The Alkali Metals • Have 1 valence electron…extremely reactive. • The reactivity increases from the top of Group 1A to the bottom. • Li, Na, K, Rb, Cs, Fr
The Halogens • 7 valence electrons • F, Cl, Br, I, At • Despite their physical differences, the halogens have similar chemical properties.
The Noble Gases • Group 18 • The noble gases are colorless and odorless and extremely unreactive. • He, Ne, Ar, Kr, Xe, Rn
How Ions are formed! • When an alkali metal or alkaline earth metal bond with a halogen. • The alkali metals gives a halogen an electron. • The alkali metal becomes a cation (positive) • The halogen becomes an anion (negative).
Covalent Bonds • When elements share valence electrons equally!!
Law of Conservation of Mass • Chemical Equations • Reactants on left • Products on right • Number of molecules on left has to equal number of molecules on right • These equations are said to be balanced. There are six molecules of Carbon on the left, and six on the right.
Kinetic Energy • Kinetic is moving energy. • The faster it goes the more energy has • More temperature = more kinetic energy.
Potential Energy • Potential Energy is essentially height! • If it is above the ground is has potential energy. • The higher it is the more potential energy it has • Elastic potential energy • If you stretch a substance it has potential energy
Check out how the speed changes as it goes down the hill This was a test question a couple of years ago…. It asked where would the cart be going the fastest…..it goes the fastest at the bottom!