Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
34 Cards in this Set
- Front
- Back
|
atom
|
the smallet particle of an element
|
|
|
element
|
A type of matter in which all the atoms are the same
|
|
|
radioactive decay
|
The breakdown of a radioactive element, releasing particles and energy
|
|
|
half-life
|
The time it takes for half of the atoms of a radioactive element to decay
|
|
|
geologic time scale
|
a record of the geologic events and life forms in Earth's history
|
|
|
era
|
one of the 3 long units of geologic time between the Precambrian and the present
|
|
|
period
|
one of the units of geologic time into which geologists divide eras
|
|
|
comet
|
a ball of ice and dust that orbits the sun
|
|
|
continental drift
|
the slow movement of the continents over earths surface caused by forces inside earth
|
|
|
invertebrate
|
an animal without a backbone
|
|
|
vertebrate
|
an animal with a backbone
|
|
|
amphibian
|
a vertebrate that lives part of its life on land part of its live in water
|
|
|
reptile
|
a vertebrate with scaly skin that lays eggs with tough, leathery skin
|
|
|
mammal
|
a warm-blooded vertebrate that feeds it young milk
|
|
|
mass extinction
|
when many types of living things become extinct at the same time
|
|
|
fossil
|
the preserved remains or traces of living things
|
|
|
sedimentary rock
|
the type of rock that is made of hardened sediment
|
|
|
mold
|
a fossil formed when an organism buried in sediment dissolves, leaving a hollow area
|
|
|
cast
|
a fossil that is a solid copy of an organism's shape, formed when minerals seep into a mold
|
|
|
petrified fossil
|
a fossil in which minerals replace all or part of an organism
|
|
|
carbon film
|
a type of fossil consisting of an extremely thin coating of carbon on rock
|
|
|
trace fossil
|
a type of fossil that provides evidence of the activities of ancient organisms
|
|
|
paleontologists
|
a scientist who studies fossils to learn about organisms that lived long ago
|
|
|
scientific theory
|
a well-tested concept that explains a wide range of observations
|
|
|
evolution
|
the process of by which water all the different kinds of living things have changed over time
|
|
|
extinct
|
describes a type of organism that no longer exists anywhere on Earth
|
|
|
relative age
|
the age of a rock compared to the ages of rock layers
|
|
|
absolute age
|
the age of a rock given as the # of years since the rock formed
|
|
|
law of superposition
|
the geologic principle that states that in horizontal layers of sedimentary rock,each layer is older than the layer above it and younger than the layer below it
|
|
|
extrusion
|
an igneous rock layer formed when lava flows onto Earth's surface and hardens
|
|
|
intrusion
|
an igneous rock layer formed when magma hardens beneath Earth's surface
|
|
|
fault
|
a break or crack in Earth's lithosphere along which rocks move
|
|
|
index fossil
|
fossils of widely distributed organisms that lived during only one short period
|
|
|
uncomformity
|
a place where an old, eroded rock surface is in contact with a newer rock layer
|
