MID TERM REVIEWBig Idea #1:

Earth Scientists use repeatable observations and testable ideas to understand and explain our planet

Big Idea #2:Earth is a Water Planet

BIG IDEA #1:

Earth Scientists use repeatable observations and testable ideas to understand and

explain our planet.

ENERGY THAT DRIVES EARTH’S 4-SYSTEMSWHAT’S THE CONNECTION?

HOW DO SCIENTISTS THINK?

Critical thinking Strong Observations Extensive Documentation Collaboration

CREDIBLE ONLINE SOURCES

DATA VS EVIDENCETURN DATA INTO EVIDENCE

factual information as measurements or statistics used as a basis for reasoning

• something that furnishes proof• something submitted to ascertain the truth of a matter.

TYPES OF DATA

Qualities VS Quantity

SHOW ME THE EVIDENCE

• Direct• Indirect•Modeling

HOW DO WE KNOW EARTH HAD AN ICE AGE?

EVIDENCE: DIRECT & INDIRECTEarth’s interior

Direct Evidence: Rock Samples

Indirect Evidence :Seismic Waves

SCIENTIFIC MODELSEXPLAINS SCIENTIFIC CONCEPTS

Accurate & Inaccurate

BIG IDEA #2

Earth is a Water Planet

WHY IS THIS IMPORTANT?WHAT IS THE CONNECTION?

LETS TALK H2O VOCAB

Surface Tension

DesalinationSalinity

Density Formula

Capillary Action

Specific Heat

Solvent

THE SCIENCE OF WATERWATER’S 7-UNUSUAL PROPERTIES1. Stronger than normal bonds2. High Surface Tension3. High Boiling Temperatures4. High Specific Heat5. Universal Solvent6. Density of the solid is less than at a liquid state7. Adhesion, Cohesion, Capillary Action

–

FORMING A WATER MOLECULE

Unequal attraction to bonding electrons Oxygen is a strong

electron grabber (high electronegativity)

Hydrogen’s electron tends to hang out close to oxygen, leaving H’s positively charged

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++H -

O +O +

WATER IS A POLAR MOLECULE Unequal distribution

of charges on the water molecule make it a polar moleculeOne end is more

negative, and one end is more positive

More positive ends

More negative end

- means partial negative charge+ means partial positive charge

ELECTRON DENSITY IS UNEVEN The electron density

around the oxygen atom in a water molecule is about 10X greater than the hydrogen atomsThis non-uniform

distribution of positive and negative charges, called a dipole, leads to H2O unusual behavior

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Source: http://www.llnl.gov/str/October05/Mundy.html

Dark Blue= high densityLight Blue= low density

UNUSUAL PROPERTIES

LETS TALK OCEAN

WHERE DOES THE SALT COME FROM?

WHAT INCREASES & DECREASES SALINITY?

1. OCEAN LAYERS FROM THE SHORE

1. OCEAN LAYERS DEPTH: 3-ZONES

2. OCEAN VARIATIONS

Temperature: Thermocline

Density: Pycnocline

WATER ON A GLOBAL PERSPECTIVE= UNEQUAL HEATING

Lon

git

ud

eLatitude

3. OCEAN CURRENTSWhat drives them?How do they form?Effect of cold currents on climate?What is the role in maintaining Earth’s heat balance?

2-Types: Density currents Deep ocean currents

4. WAVESWAVES TRANSFERS ENERGY FROM ONE POINT TO ANOTHER

5. TIDESDAILY CHANGES IN THE ELEVATION OF THE OCEAN SURFACE