Presentation on theme: "M ID T ERM R EVIEW Big Idea #1: Earth Scientists use repeatable observations and testable ideas to understand and explain our planet Big Idea #2: Earth."— Presentation transcript:
M ID T ERM R EVIEW Big Idea #1: Earth Scientists use repeatable observations and testable ideas to understand and explain our planet Big Idea #2: Earth is a Water Planet
B IG I DEA #1: Earth Scientists use repeatable observations and testable ideas to understand and explain our planet.
E NERGY THAT D RIVES E ARTH ’ S 4-S YSTEMS W HAT ’ S THE C ONNECTION ?
H OW D O S CIENTISTS T HINK ? Critical thinking Strong Observations Extensive Documentation Collaboration
D ATA VS E VIDENCE T URN D ATA INTO E VIDENCE 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.
W HY IS THIS IMPORTANT? W HAT IS THE CONNECTION?
L ETS TALK H 2 O V OCAB Surface Tension Desalination Salinity Density Formula Capillary Action Specific Heat Solvent
T HE S CIENCE OF W ATER W ATER ’ S 7-U NUSUAL P ROPERTIES 1. Stronger than normal bonds 2. High Surface Tension 3. High Boiling Temperatures 4. High Specific Heat 5. Universal Solvent 6. Density of the solid is less than at a liquid state 7. Adhesion, Cohesion, Capillary Action
–– F ORMING A W ATER M OLECULE 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 16 + + H - O +
W ATER IS A P OLAR M OLECULE Unequal distribution of charges on the water molecule make it a polar molecule One end is more negative, and one end is more positive More positive ends More negative end - means partial negative charge + means partial positive charge
E LECTRON D ENSITY IS U NEVEN The electron density around the oxygen atom in a water molecule is about 10X greater than the hydrogen atoms This non-uniform distribution of positive and negative charges, called a dipole, leads to H 2 O unusual behavior 18 Source: http://www.llnl.gov/str/October05/Mundy.html Dark Blue = high density Light Blue= low density