chapter10 Flashcards
a scientist that studies fossils is called what?
paleontologist
gradual change in living things over long periods of time is called
evolution
radioactive dating is used to do what
determine the absolute age of rocks
what happens during radioactive decay
atoms of one element break down to form atoms of another element
the half life of a radioactive element is what
time it takes for half of the radioactive atoms to decay
when all the atoms of a particular type of matter are all the same it is called
element
what is the law of superposisition used for
determine the realtive age of rocks
in a horizontal sedimentary rock what is at the bottom
the oldest layer
magma that forces its way into rocks and hardens is called what
intrusion
what is intrusion
a hardened layer of magam beneath Earths surface
what is extrusion
hardened layer of lave on Earths surface
what do fossils provide us
evidence of changes in Earths surface, how environments on Earth have changed over time and how groups of organisms have changed over time
when do most fossils form
when organisms die and are buried in sediment
mold,cast,petrified fossil, carbon film trace are all types of what
fossils
is a cast a solid copy of the shape of an organisms?
yes
true or false: a mold is a hollow are in sediment in the shape of an organism
true
true or false: molds and cast are the least common types of fossils
false: the are the most common
true or false: carbon film consists of an extremenly thick film of carbon on rock
false: thin film
trace fossils provide evidence of what
activities of ancient organisms
when does a petrified fossil form
when minerals replace all or part of an organism
where are fossils almost always found
sedimentary rock