Key Points of Atoms

Proton–positive charge and located in the nucleus

Neutron–neutral charge and located in the nucleus

Electron–negative charge and in the energy levels outside of the nucleus

Atomic Number tells the number of protons, neutrons and electrons the atom should have

Isotope–a atom that has more or less neutrons in the nucleus than its atomic number dictates

EXCEPTION:  Hydrogen does not have a neutron in the nucleus–it is the odd man out

8th Grade Slideshow

Click on the link below to view the 8th grade slideshow 2008-2209

http://smilebox.com/playBlog/4f5459314f444d794d413d3d0d0a&blogview=true

Ocean Water Movement Review

Currents

Surface Currents–currents that are found on the surface of the water

Affected by:  Global Wind, Coriolis Effect, and Continental Deflection

Deep Currents–currents that are found in the deep part of the ocean

Affected by:  Changes in salinity and Decreases in Temperature

Climate and the Currents

Warm Water Currents–bring warmer temperatures and more moisture than the area should receive

Cold Water Currents–bring cooler temperatures and a dry climate to the area

Waves

Crest–Top part of the wave

 Trough–Lowest part of the wave

Wavelength–measurement from crest to crest or trough to trough (measured in meters)

Wave height–measurement from crest to trough of a single wave (measured in meters)

Wave period–time measurement for the crest of one wave and the next wave crest to pass a fixed point (measured in seconds)

 Shallow water waves–when the wave begins to interact with the ocean floor  

 Deep water waves–when the depth of the water is more than 1/2 the wavelength of the wave–no interaction with the ocean floor

Tides

High Tide–the highest point of water during the day

Low Tide–the lowest point of water during the day

Spring Tide-When the Sun, moon, and earth are in a straight line–HIGH high tides and LOW low tides

Neap Tide–When the Sun, moon, and earth are at a right angle (L-shaped)–Very little difference between high and low tides

Oceans:Review

Life Categories

Plankton–floating organisms (drifters)–Phytoplankton (plant-like)–Zooplankton (animal-like)–Usually found near the top because they need sunlight to photosynthesize

Nekton–active swimmers in the ocean water–Examples: Whales, Fish, Dolphins, Sea Turtles–Found in all areas of the ocean

Benthos–live on or in the ocean floor–Examples: Marine Worms, crabs, coral

Ocean Life Zones

Intertidal–from the high tide to low tide area–very changing area–waves crashing, exposed to air when the tide recedes, and the currents are constantly pulling on organisms here–(Ex) periwinkle snails, coquinos, sand fiddlers

Neritic–area from the low tide mark to the end of the continental shelf–most diverse in life because it has low water pressure, warm constant temps,  very little wave movement–(Ex) coral, blue tang, clown fish

Open-Ocean Zones–Divided into two zones

Bathyal–open ocean top part of the water, top gets sunlight–bottom does not and is dark (Ex) Whales, giant squid, sea turtles

Abyssal–deep part of the ocean, water is extremely cold here–(Ex) Angler fish, viper fish, bio-luminous creatures

Make-up of Ocean Water

Dissolved salts–majority is Sodium Chloride

Dissolved gases–CO2 and O2

Pure Water

Salinity–measure of the amount of dissolved salts in the water

Desalination–removal of salt from water to get fresh water–used in middle east and areas where fresh water is scarce

Ocean Exploration–just a few ways

Sonar                                  Satellites

ROV                                     Sounding Ropes

Submersibles                  SCUBA

Vessels (floating labs)

Ocean Resources

Food–Fish, seaweed, clams, oysters, mussels, kelp, etc

Fresh water–through desalination

Oil/Natural Gas–gained through drilling into the ocean floor

Seafloor minerals–gained by mining the nodules off the ocean floor

Energy–tidal and wave energy

Ocean Pollution

Non-Point–hard to find the source of this–All of us contribute to this pollution–from dropping a wrapper on the ground to riding in a car/bus/vehicle

Point–one source easier to find

Sludge Dumping–taking the solid part from water treatment plants and dumping it off the coast

Trash Dumping–taking the trash from cities on barges out into the deep ocean and dumping the trash in to the water

Oil Spills–tankers/pipelines dumping the oil into the ocean

Acts to Stop Pollution

Clean Water Act–put EPA in charge of giving out permits for dumping waste into the ocean

US Marine Protection, Research, and Sanctuaries Act–prohibts the dumping of any materials that are harmful to sea life, humans, or businesses that depend on the ocean

1989–Treaty signed by 64 countries that prohibits the dumping of certain metals, plastics, and radioactive materials

EOG Preparation

The EOG tests are fast approaching.  This year students will be taking a science EOG in addition to the Reading and Math.  We are preparing in class by using sample EOG style questions during our daily bellringers.  Students will also be using AC time during 4th quarter to get EOG prep in all three areas. 

Below are some website that students can use to help prepare for the science EOG:

http://www.ncpublicschools.org/docs/accountability/testing/eog/science/20071204gr8sci.pdf

Water Unit

We are underway in the unit of hydrology (aka WATER)

Students will be learning about:

Hydrologic (Water) Cycle

Rivers

Water Underground  

Water Quality

Water Pollution

Oceans

Ocean Life/Ecosystems

Ocean Movement

Resources from the Ocean

Ocean Pollution

Ocean Exploration

Don’t forget the Science EOG is coming up!  Start reviewing your notes on Inquiry, Chemistry and Water!

Chemical Risks and Benefits

Chemical Risks–many chemicals are safe, but some can be harmful.  Even helpful chemicals can have risks when you are exposed.  Exposure means when you come in contact with a chemical.  Most of us are exposed to thousands of chemicals each day, but the greater the exposure to dangerous chemicals the more likely your health can suffer.  Individual Susceptibility can be a major factor in how a chemical can affect you. Individual Susceptibility is your individual risk about how a dangerous chemical can affect you.  Some individuals are very susceptible to penicillin and become very ill if they take it.

Diseases associated with chemicals: cancer, autoimmune diseases, diabetes, birth defects, learning and behavioral disorders, kidney disease, heart disease, and asthma.

Chemical Benefits–lots of chemicals make our lives much better because of their use.  **Medicine is a major chemical benefit.  Some chemicals are natural (made in nature or by natural processes) and others are synthetic (man-made).  For a medicine to be effective there are many different areas that need to be considered.  Potency–the power of the medicine–for a medicine to work you need a certain amount–too much and it causes harm–too little and you don’t get the desired effect.  Side effects–an effect that differs from the intended effect–benadryl is used to stop allergic reactions (itchy eyes, runny nose, etc)–but the side effect is that it makes you tired.  Dose–the amount of medicine that needs to be taken at one time.  Dose depends on the weight of the individual taking the medicine.  Smaller doses for smaller children, larger doses for larger adolescents.

**Food Preservatives–allow food to last longer before it spoils

**Pesticides–kill insects, weeds, and other pests that damage crops

**Fertilizers–improves the soil quality to allow more and better crop development

**Sanitation–cleaning water, disposing of solid and liquid waste, clean living conditions

Covalent Bonding and Metallic Bonding

Covalent Bonding is the sharing of electrons between two or more atoms.

Covalent Bonding happens only between elements of the same classification.  Nonmetals will covalent bond with other nonmetals.

Some elements bond with themselves and form a diatomic element.

H—H  (H2)

O==O  (O2)

A single line between atoms represents one shared pair of electrons (–)

A double line between atoms represent two shared pairs of electrons (==)

Metallic bonding–occurs when an electron from a metal roams freely among the metal ions.  Instead of that electron belonging to one metal ion, it roams and interacts with all the metal ions.

These freely moving electrons allow metals to bend, be pulled (ductility), and be pounded into sheets (malleability).  The electrons move throughout the metal and are not tied to one metal ion, so at all times a metal ion has a negative electron near it.  In a regular covalent or ionic bond, the atoms have to be right next to each other because they are bonded tightly together.

Ionic Bonding

Metals–form positive ions–lose electrons–because they have only a few in their outer energy level (valence electrons)

Nonmetals–form negative ions–gain electrons–because they have a full set almost in their outer energy level (valence electrons)

An ionic compound has a neutral charge–because it is made up of a positive ion and a negative ion that cancel each other out.

Lithium has one valence electron–it will lose that one electron and form a positive ion that has the charge +1.

Fluorine has seven valence electrons–it needs one electron to make a full outer shell of eight–it will gain one electron and have a charge of -1.

Chemical Bonding: Valence Electrons

Valence Electrons–electrons in the outer most energy shell

Group 1-2 and 13-18 are easy to figure out the number of valence electrons in their outer layer–>it is the number in the ones place.  Group 1-1 valence electron, Group 2-2 valance electrons, Group 13–>3 valence electrons.

Knowing the number of valence electrons allows you to figure out if the element will bond and how many bonds it needs.

If an atom has three valence electrons–>then it will need five more electrons to have a full outer layer (full outer layers have 8 valence electrons)

Electron Dot Diagrams make looking at valence electrons so much easier.

Example:                           .

                                     .    Mg

Magnesium–has 2 valence electrons, which are represented as dots around the symbol.  Also I know that Mg needs 6 more electrons to be full.

                                                      

Compounds and Mixtures

Compounds–two or more elements that are chemically combined and can only be separated by chemical changes   EXAMPLE:  WATER  (H2O)  H–O–H

Mixtures–two or more substances that are not chemically combined and can be separated by physical means

Three types of mixtures:

Solution–doesn’t scatter light, evenly dispersed particles that look like a single substance, can be separated by evaporation   EXAMPLE: Sugar and water

Suspension–scatters light, particles are dispersed but the large particles will settle out over time, separated by filtering  EXAMPLE:  Snow globe

Colloid–scatters light, particles are dispersed and will not settle out, cannot be separated by filtering   EXAMPLE:  JELLO