Earth Science Semester 1

DBA 1

Astronomy

The study of objects beyond Earth’s atmosphere.

Atmosphere

The blanket of gases that surrounds our planet.

Geosphere

The area from the surface of Earth down to its center.

Geology

The study of materials that make up Earth, the processes that form and change these materials, and the history of the planet and its life forms since its origin.

Biosphere

Includes all organisms on Earth as well as the environments in which they live.

Oceanography

The study of Earth’s oceans, which cover nearly three fourths of the planet.

Environmental Science

The study of the interactions of organisms and their surroundings.

Meteorology

The study of the forces and processes that cause the atmosphere to change and produce weather.

Hydrosphere

All the water on Earth, including the water in the atmosphere.

Scientific Model

An idea picture, a system, or a mathematical expression that represents the concept being explained.

Scientific Theory

An explanation based on many observations during repeated investigations.

Scientific Law

A principle that describes the behavior of a natural phenomenon.

Cartography

The science of mapmaking.

Longitude

The distance in degrees east or west of the prime meridian.

Equator

Horizontally circles Earth halfway between the North and South poles, separating Earth into two equal halves.

Latitude

Lines on a map running parallel to the equator. The distance in degrees north or south of the equator.

Prime Meridian

Reference point of longitude that represents 0 degrees of longitude.

International Date Line

Is a 180 degree meridian that serves as the transition line for calendar days.

Map Projection

Made by transferring points and lines on a globe’s surface onto a sheet of paper.

Contour Interval

The difference in elevation between two side by side contour lines.

Mercator Projection

A map that has parallel lines of latitude and longitude.

Geologic Map

Used to show the distribution, arrangement, and type of rocks located below the soil.

Topographic Map

Show changes in elevation of Earth’s surface.

Map Legend

Explain what the map symbols represent.

Contour Line

Connects points of equal elevation.

Map Scale

The ratio between distances on a map and actual distances on the surface of Earth.

Matter

Anything that has volume and mass.

Isotope

Atoms of the same element that have the same number of protons but different number of neutrons and different mass numbers.

Electron

Has little mass but has a negative electric charge that is exactly the same magnitude as the positive charge of a proton.

Neutron

A particle with approximately the same mass as a proton, but is electrically neutral meaning it has no electric charge.

Nucleus

It made up of protons and neutrons.

Element

A substance that cannot be broken down into simpler substances by physical or chemical means.

Mass Number

The sum of the protons and neutrons.

Atomic Number

The number of protons in an atom’s nucleus.

Proton

A tiny particle that has mass and a positive electric charge.

Ion

An atom that gains or loses an electron and has a net electric charge.

Compound

A substance that is composed of atoms of two or more different elements that are chemically combined.

Chemical Reaction

The change of one or more substances into other substances.

Molecule

Composed of two or more atoms held together by covalent bonds.

Base

A substance that produces hydroxide ions in water.

Covalent Bond

The attraction of two atoms for a shared pair of electrons that holds the atoms together.

Acid

A solution containing a substance that produces hydrogen ions in water.

Metallic Bond

Allows metals to conduct electricity because the electrons can move freely throughout the entire solid metal.

Ionic Bond

The attractive force between two ions of opposite charge.

Chemical Bond

The force that holds together the elements in a compound.

Solution

A homogeneous mixture where the component particles cannot be distinguished from each other even though they still retain their original properties.

Crystalline Structure

What most solids are, because they are arranged in regular geometric patterns.

Glass

A solid that consists of densely packed atoms arranged randomly.

Evaporation

The process of change from a liquid to a gas at temperatures below the boiling point.

Plasma

Hot, highly ionized, electrically conducting gases.

Condensation

When gas is cooled to the boiling point and it becomes a liquid.

Sublimation

The slow change of state from a solid to a gas without intermediate liquid state.

Mineral

A naturally occurring, inorganic solid, with a specific chemical composition and a definite crystalline structure.

Streak

The color of a mineral when it is broken up and powdered.

Fracture

What minerals have when they break up with rough or jagged edges.

Luster

The way that a mineral reflects light from its surface.

Crystal

A solid in which the atoms are arranged in repeating patterns.

Specific Gravity

The ratio of the mass of a substance to the mass of an equal volume of water at 4 degrees Celsius.

Cleavage

What a mineral has when it splits easily and evenly along one or more flat planes.

Hardness

A measure of how easily a mineral can be scratched.

Ore

What a mineral is if it contains a valuable substance that can be mined at a profit.

Tetrahedron

A geometric solid having four sides that are equilateral triangles, resembling a pyramid.

Gem

Valuable minerals that are prized for their rarity and beauty. They are very hard and scratch resistant.

Lava

Magma that flows out onto Earth’s surface.

Igneous Rock

Forms when lava or magma cools and crystallizes.

Partial Melting

The process where some minerals melt at relatively low temperatures while other minerals remain solid.

Intrusive Rock

Rocks that form when magma cools and crystallizes below Earth’s surface.

Extrusive Rock

Forms when magma that cools and crystallizes on Earth’s surface.

Texture

The size, shape, and distribution of the crystals or grains that make up a rock.

Basaltic Rock

Also called mafic rocks, are dark colored, have lower silica contents, and contain mostly plagioclase and pyroxene.

Granitic Rock

Also called felsic rocks, are light colored, have high silica contents, and contain mostly quartz and feldspar.

Vesicular Texture

The spongy appearance of rocks.

Porphyritic Texture

Characterized by large, well formed crystals surrounded by finer grained crystals of the same mineral or different minerals.

Sediment

Small pieces of rock that are moved and deposited by water, wind, glaciers, and gravity.

Lithification

The physical and chemical processes that transform sediments into sedimentary rocks.

Cementation

Occurs when mineral growth glues sediment grains together into solid rock.

Bedding

The primary feature of sedimentary rocks that is horizontally layering.

Graded Bedding

Bedding in which the particle sizes become progressively finer and lighter toward the top layers.

Cross Bedding

Is formed as inclined layers of sediment are deposited across a horizontal surface.

Clastic Sedimentary Rock

The most common sedimentary rocks that are formed from the abundant deposits of loose sediments that accumulate on Earth’s surface.

Evaporite

Layers of chemical sedimentary rocks that form.

Porosity

The percentage of open spaces between grains in a rock.

Clastic

The word that comes from the Greek word “klastos”, meaning broken.

Weathering

The process in which materials on or near Earth’s surface break down and change.

Mechanical Weathering

A type of weathering in which rocks and minerals break down into smaller pieces.

Frost Wedging

The freeze-thaw cycles of water in the cracks of rocks.

Exfoliation

The process b y which outer rock layers are stripped away.

Chemical Weathering

The process by which rocks and minerals undergo changes in their composition.

Oxidation

The chemical reaction of oxygen with other substances.

Erosion

The removal of weathered rock and soil from its original location.

Gully Erosion

What rill erosion evolves into when a channel becomes deep and wide from further erosion.

Rill Erosion

Develops when running water cuts small channels into the side of a slope.

Deposition

The process where minerals are dropped into another location after they are transported.

Soil

The loose covering of weathered rock particles and decaying organic matter called humus, overlying the bedrock of Earth’s surface, and serves as a medium for the growth of plants.

Residual Soil

A soil whose parent material is the local bedrock.

Transported Soil

Soil that develops from the parent material that has been moved far from its original location.

Soil Profile

A vertical sequence of soil layers.

Soil Horizon

A distinct layer within a soil profile.