7th Grade Science Ch 1

astronomy

the study of physical things beyond the earth's atmosphere

earth science

the study of the earth and the universe around it

environmental science

the study of the relationship between organisims and the enviroment

geology

the study of the solid earth

meterology

the study of the atmosphere

oceanography

the study of the earth's oceans

carbon-14 dating

method used to determine the absolute age of remains that were once living

naturalism

the belief that matter and energy are all that exist and that undriected natrual processes formed the universe

theism

the belief that the universe was created pruposefully by a supernatural being

varves

the light and dark layers of sediments deposited in a yearly cycle

contour line

a line on a map that joins points of equal elevation

latitude

the distance in degrees north or south of the equator

longitude

the distance in degrees east or west of the prime merdian

projection

a system of lines drawn on a flat surface to represent curves

mineral

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

mineralogy

the study of minerals, including their composition, properties, and classification.

nonsilicate mineral

a mineral composed of elements or bonded groups of elements other than bonded silicon and oxygen

silicate mineral

a mineral formed by bonded silicon and oxygen atoms

cleavage

a mineral’s tendency to split along definite, flat surgaces

density

the mass per unit of volume of a substance

fracture

a mineral’s tendency to break along irregular lines

hardness

a mineral’s resistance to being scratched

luster

the way a mineral reflects light, which can be described as metallic or non-metallic

streak

the color of the powder left by a mineral when it is rubbed against a hard, rough surface

silicate

a mineral composed primarily of silicon and oxygen, often forming the building blocks of many rocks and minerals.

oxide

a mineral that contains oxygen and one or more metal elements, typically found in various ores.

sulfates

a group of minerals that contain the sulfate ion, $ext{SO}_4^{2-}$, and are commonly found in evaporite deposits and as secondary minerals.

sulfide

a group of minerals that consist primarily of sulfur combined with one or more metals. They are typically found in ore deposits and can form under a variety of geological conditions.

halide

a group of minerals that consist of halogen elements combined with one or more metals. Halides are often found in evaporite deposits and can display a range of physical properties depending on their composition.

actinide

a group of 15 elements in the periodic table that includes actinium and the series of elements from thorium to lawrencium. These elements are known for having partially filled f-orbitals and are radioactive.

extrusive rock

an igneous rock formed when lava cools on the earth’s surface

felsic rock

a light-colored igneous rock rich in silica and aluminum, typically formed from the cooling of magma

igneous rock

a rock formed from cooled and harded magma

intrusive rock

an igneous rock formed when magma cools beneath the earth’s surface

lava

the magma that has reached the earth’s surface

mafic rock

the dark colored, heavy igneous rock that is rich in iron, magnesium, and calcium

magma

the melted rock beneath the earth’s surface

clastic rock

a sedimentary rock made of rock particles and fragments deposited by water, wind, or ice

lithification

the process that transforms layers of rock fragments into sedimetary rock

sedimentary rock

a rock formed from sediments that have been compacted and cemented together

sediments

particles of minerals, rock fragments, shells, leaves, and the remains of once-living things

shale

a clastic rock composed of silt and clay sized particles in flat layers

contact metamorphism

metamorphism that occurs when the heat of magma comes in contact with existing rocks

dynamic metamorphism

metamorphism that is produced by mechanical force

foliated structure

a rock structure with visible layers or bands aligned in planes

metamorphic rock

a rock formed when the structure and mineral composition of existing rocks change because of heat, pressure, or chemical reactions

metamorphism

the process of change in the structure and mineral composition of a rock

nonfoliated structure

a rock structure with no visible layers or bands

regional metamorphism

metamorphism that occurs when large regions of the earth’s crust are affected by high temperatures and pressures

core

the central portion of the earth

inner core

the solid center of the earth

magnetosphere

the area around the earth that is affected by earth’s magnetic field

outer core

the liquid layer of the earth’s core that surrounds the inner core

P wave

the fastest seismic wave, which travels through solids, liquids, and gases

seismic wave

a wave that travels only through solids

S waves

secondary waves that only travel through a solids

athenosphere

the layer of the upper mantle composed of low-density rock material that is semiplastic

convection current

the circle movement of heated materials to a cooler area and cooled materials to a warmer area

lithosphere

the outermost, rigid layer of the earth composed of the stiff upper layer of the mantle and the crust

mantle

the portion of the earth’s interior extending from the outer core to the bottome of the crust

Moho

the boundary between the mantle and the crust

continental crust

the crust on which the continents rest

crust

the thin, hard outer layer of the earth

oceanic crust

the crust beneath the oceans