Minerals Layers of the Earth

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1 Minerals Mineral is a substance that is: Solid Formed in Nature Has a Crystalline Structure Minerals are Identified by: Luster The way a mineral reflects light (metallic, non-metallic) Hardness- The resistance to being scratched Texture- how it feels. Determined by the grains in the mineral Cleavage/Fracture- How the Mineral breaks Cleavage Breaks on smooth flat surfaces Fracture Breaks unevenly Color The color the mineral appears Streak The color of the mineral when scratched on a hard surface Moh s Hardness Scale is used to determine a mineral s hardness rating If a mineral is Softer than an object it will be scratched If a mineral is Harder than an object it will NOT be scratched Layers of the Earth There are 4 Layers of the Earth o Crust- Outer most layer, coolest and thinnest layer, made of solid rock, broken into pieces; continental crust and oceanic crust o Mantle- thickest layer, semi-solid magma (liquid rock), contains convection currents o Outer Core- only liquid layer, 2 nd hottest, and 2 nd thinnest layer, made of metals, controls the magnetic field of the earth o Inner Core- solid, made of metals (nickel and iron), hottest layer

2 Tectonic Plates Earth s crust is broken into pieces called Tectonic Plates There are 2 types of Tectonic Plates o Continental thicker and less dense o Oceanic thinner and More dense These plates are constantly moving because of convection currents Convection currents form in the mantle where hot dense magma rises, spreads out, cools down and then sinks These currents causes the plates to collide, separate or slide past each other There are 3 types of plate boundaries o Convergent 2 plates collide o Divergent 2 plates separate o Transform- 2 plates slide past each other Each type of plate boundary has very specific geologic features or landforms that occur o Convergent : Tall mountains (continental/continental) Deep Ocean Trenches (Oceanic/Oceanic) Volcanic Mountains (Continental/Oceanic) *** Subduction zones forms when one plate is pulled under the other (always the oceanic)*** o Divergent: Seafloor Spreading and Mid Ocean Ridges (Oceanic) Rift Zones/Rift Valleys (Continental) o Transform: Faults and Earthquakes

3 Scientific Method Scientific Method is used to guide an investigation. By following its steps/guidelines we can make sure our results and conclusion are valid and reliable. You hypothesis is an essential piece When you develop a hypothesis it helps by: o Guiding your investigation o Identify your variables correctly Identifying and controlling your variables allows your investigation to be reliable There are 3 types of Variables: o Independent the variable you will CHANGE o Dependent the variable you will MEASURE o Controlled the variable you will HOLD CONSTANT Hypothesis should be written in correct format: o If, then. (Independent Variable) (Dependent Variable) Example: If a bowler wears bowling shoes then the bowling score will increase. After you conduct your investigation and have gathered data you will need to analyze it Create graphs to represent the data o Easier to understand what the data is telling you Graphs are used to tell certain stories o Pie percentages o Line changes over time o Bar compare sets of data o Histogram show ranges of large sets of data

4 Rock Cycle The earth s surface is constantly changing because of the Rock Cycle Mountains, valleys, rivers and many other features are created or destroyed due to: o Weathering- breaking down rocks into sediment o Erosion Moving the sediment from one place to another o Deposition the sediment stops moving There are 3 types of rocks on earth o Igneous o Sedimentary o Metamorphic Each type of rock is formed by specific processes o Igneous forms when magma cools (crystallization) o Metamorphic heat and pressure changes the rock into something different (metamorphism) o Sedimentary Squeezing (compaction) and Gluing (Cementation) of sediment together These rocks can change from one to the other through the rock cycle. Fossils We can look at fossils found in the ground and interpret what the environment used to be like o For example: If in the deepest layer of a core sample we found a fish fossil and then in a more recent layer we found a fern sample we could infer that in the past the area was once covered in water and that fish lived in it. More recently it was more of a forest where ferns grew.

5 Chemistry All the elements found on earth are organized on the Periodic Table of Elements The Periodic Table is organized into: o Periods rows that run horizontally o Groups or Families columns that run vertically Each element is represented by an element box The box tells us: o Name o Symbol- abbreviation of the Name o Atomic Number the number of Protons in the Nucleus o Atomic Mass the mass of the one single atom of the element The periodic table is also organized into 3 categories o Metals found to the right of the zig-zag line o Non-Metals found to the left of the zig-zag line o Metalloids found along the zig-zag line Elements can be combined to form compounds and mixtures o Elements are pure- only one type of atom (example: C or Ca) o Compounds 2 or more elements CHEMICALLY combined (example: NaCl) o Mixtures Elements and Compounds NOT chemically combined (example: salad or air) When looking at the chemical equation of a substance you can tell the difference between and element and compound by counting the number of CAPITAL letters in the equation) o If there is only 1 capital letter than it s an element o If there is more than 2 capital letter than it s a compound. Chemical reactions combine elements together or break them apart You know a chemical reaction has occurred by looking for evidence. o Gas forming: see bubbles form o Precipitate forms o Color change

6 o Temperature change