science vocab

Question 1

uniformitarianism

Answer 1

a principle that states that geologic processes that occurred in the past can be explained by current

Question 2

catastrophism

Answer 2

a principle that states that geologic change occurs suddenly

Question 3

paleontology

Answer 3

the scientific study of fossils

Question 4

relative dating

Answer 4

any method of determining whether and event or object is older of younger than other events or objects

Question 5

absolute dating

Answer 5

any method of measuring the age of an event or object in years

Question 6

superposition

Answer 6

a principle that states that younger rocks lie above older rocks if she layers have not been disturbed

Question 7

isotope

Answer 7

an atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons(and thus a different atomic mass)

Question 8

half-life

Answer 8

The time needed for half of a sample radioactive substance to undergo radioactive decay

Question 9

fossil

Answer 9

the remains of physical evidence of an organism preserved by geologic processes

Question 10

trace fossil

Answer 10

a fossilized mark that is formed in soft sediment by the movement of an animal

Question 11

Mold

Answer 11

a fungus that grows in the form of multi cellular filaments called hyphae. In contrast, fungi that can adopt a single-celled growth habit are called yeasts.

Question 12

cast

Answer 12

a type of fossil that forms when sediments fill in the cavity left by a decomposed organism

Question 13

unconformity

Answer 13

a break in the geologic record created when rock layers are eroded or when sediments is not deposited for a long period of time.

Question 14

mass extinction

Answer 14

A mass extinction is a relatively sudden, global decrease in the diversity of life forms.

Question 15

Jurassic period

Answer 15

The Jurassic Period was the second segment of the Mesozoic Era

Question 16

radioactive decay

Answer 16

the process in which a radioactive isotope tends to break down into a stable of isotope of the same element or another element

Question 17

Cretaceous period

Answer 17

noting or pertaining to a period of the Mesozoic Era, from 140 million to 65 million years ago, characterized by the greatest development and subsequent extinction of dinosaurs and the advent of flowering plants and modern insects. noun. 3. (initial capital letter) Geology. the Cretaceous Period or System.

Question 18

Devonian period

Answer 18

The Devonian is a geologic period and system of the Paleozoic Era

Question 19

Quaternary period

Answer 19

the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy

Question 20

Permian period

Answer 20

The Permian period lasted from 299 to 251 million years ago* and was the last period of the Paleozoic Era.