Chemistry Retest

Any chemistry student wishing to retest "Balancing Equations" please see me and I will enroll you in e2020.

Week of 2/27/12

Chemistry

Monday- pH lecture, watch pH lecture

Tuesday- review problems/ possible lab

Wednesday- moodle pH, radioactivity simulations

Thursday- finish pH, lab

Friday - 'critical reading activity'

Physical Science

Monday- positive choices talk, watch divergent/convergent boundary lectures on moodle for Thursday

Tuesday-  boundary activity

Wednesday- computer lab (google Earth), finish group work/activity sheet/Alution Trence activity

Thursday- boundary activity

Thursday- Boxer Day Tsunami, google Earth

Week of 2/20/12

Chemistry 
 Monday- off
Tuesday - Friday - juniors ACT prep, seniors bring work to do.

Physical Science
Monday- off
Tuesday-Plate Tectonics review
Wednesday-computer lab start "google Earth" lab
Thursday-Plate Tectonics
Friday-Finish Plate Tectonics Lab

Sedimentary and Metamorphic Rocks

Let's finish-up talking about rocks.

Sedimentary Rocks:

• form from the weathering and erosion of previous rocks
• the process is- weathering, erosion, deposition, compaction, cementation
• clastic rocks form from fragments of material ex; conglomerate and sandstone
• chemical rocks form from the precipitation of minerals from water (oceans) ex; rock salt and rock gypsum
• fossils are found in sedimentary rocks, the other rock processes would destroy the fossils. Interesting fact, even ripple marks from streams or beaches can be fossilized.

Metamorphic Rocks:

• these rocks form from extreme heat and pressure placed upon pre-existing rocks.
• heat is the primary agent for contact metamorphism, this heat is supplied by nearby magma.
• during metamorphism minerals may recrystallize, crystals can grow larger and the rock will become more compact.
• running water is NOT an agent of metamorphism.

By the way Google Earth has a new version out- download it, pretty cool.

Minerals

Ternary Diagram

See this link for a review on ternary diagrams.

Igneous Rocks

Pictures courtesy of Univ of Texas Geology Dept.


Let's review some terms on Igneous Rocks:

• Intrusive rocks- those that form from cooling magma beneath the Earth's surface (ex. granite, picture on left), they will have a course-grained texture.
• Extrusive rocks- those that form from magma that has reached the Earth's surface, lava, they will have a fine- grained texture ( ex. basalt, picture on right).
• Granitic- light colored rocks contain greater amounts of feldspar (felsic).
• Basaltic- dark colored rocks contain greater amounts of magnesium (mafic).
• Porphyritic- type of rock that has two different crystal sizes.
• Remember, igneous rocks are characterized by composition and texture.
  

The Rock Cycle

ROCKS are naturally occurring solid mass of minerals, remember they have to be inorganic - so things like coal cannot be rocks because they are made from organic materials. The three major types of rocks are igneous, sedimentary and metamorphic.

Important- the energy that drives the Rock Cycle comes from the Earth's interior (igneous and metamorphic rocks) and from the Sun (weathering for sedimentary rocks).

• When magma cools igneous rocks can form intrusive (below ground) or extrusive (above ground).
• Compaction and cementation (lithification) from the weathering of surface rocks for sedimentary rocks.
• Metamorphic rocks occur deep in the ground from the processes of high temperatures and high pressures.
  

Recap on Minerals

A few more facts on minerals:

• composition and structure determines the properties of a mineral.
• density of a mineral is determined by dividing the mass by the volume
• density is a very important property of a mineral, ex: to tell if a sample of gold is gold check the density of the sample.

Mineral Identification

Physical properties of minerals include:

• crystal form- shape, arrangement of atoms
• cleavage- tendency to break with a smooth plane
• fracture-uneven breakage of a mineral
• luster- how light is reflected from the surface
• color- obvious, but not very reliable
• streak- color of a mineral in powder form
• density- ratio of mass/volume
• hardness- resistance to abrasion, using Moh's scale of hardness
  

Mineral Formation

Minerals are formed in the Earth's crust by four major processes:

• magma- molten rock in the crust, as it cools this magma crystallizes to form minerals.
• precipitation- as water evaporates, the dissolved minerals are left behind (ex. limestone, gypsum).
• high pressure/high temperature- these minerals can recrystallize deep within the Earth's crust.
• hydrothermal solutions- hot water and dissolved substances can come into contact with existing minerals, and react to form new minerals.
  

Mineral Composition

Minerals are classified by their composition, the elements that they are made of. As seen by the graph ( left) the most abundant element in the Earth's crust (by weight) is oxygen.

The major mineral groups are:

• silicates- (above right) this is the most common mineral group as it contains oxygen and silicon. ex. feldspar
  
• carbonates-contain carbon and oxygen, ex. limestone
• oxides- contain oxygen and a metal element, ex. TiO2, rutile
• sulfates/sufides- contain sulfur, hint-all minerals in this group contain sulfur. ex. pyrite
• halides- contain a halogen (salt formers) ex. halite-table salt.
• native - minerals of only one element, ex. gold
  

Minerals

Minerals typically are composed of two or more elements and have the following properties:

• inorganic- not derived from living things
• naturally occuring- not "fake"
• solids- cannot be a liquid or gas
• crystalline shape- orderly arrangement of atoms
• chemical composition- definite composition

An interesting note that "ice" from a glacier is considered a mineral.

Thanks to Philip Staublin for pointing out that there are some minerals that are considered "native minerals" composed of only one element. This is for Philip- good catch- we did cover native minerals in class but it is not going to be a test question- so I did not blog it, Mr. V.

Week of 2/6/12

A reminder to all classes. Unless instructed otherwise email me all work as a PDF attachment.

Chemistry
Monday- Lincoln Tech, watch "Kahn" lecture Balancing
Tuesday - balancing equations Ch 11
Wednesday- Ch 11, computer lab
Thursday- Ch 11
Friday- computer lab writing assignment


Physical Science
Monday- Wise choices, watch Rock lecture
Tuesday- rock samples, rock cycle
Wednesday- computer lab, 
Thursday- rock reinforcement
Friday- rock ID