Geology - Test1
What is the basic geometric shape of the elements in the silicate mineral group
a triangle
metallic bond
all electrons are SHARED b/w nucleii
What elements are common in light-colored silicate minerals?
aluminum, sodium, potassium
What are isotopes?
atoms with the SAME number of PROTONS but a DIFFERENT number of NEUTRONS
How are elements in the periodic table arranged?
by increasing atomic number
Why are non-silicates important
cause they still make up 10% of the crust
Why are minerals important?
economic value - useful: ex. bentonite - used in oil wells, paint, makeup environmental effects they're beautiful - diamonds
Ionic Bond
electrons are given up or take on and the element will have a change
What is the key characteristic of the half-life of an isotope that makes it so valuable for absolute dating?
half-life is constant
What are asteroids
left over material from the formation of the solar system
What are the 3 components of magma
liquid (while melting), solid (minerals forming as magma rises and cools), and gases
What material was used to establish the age of the earth?
meteorites and parent/daughter elements to come up with a rough estimate
meteorites
meteoroids that enter Earth's atmosphere and burn up
Alfred Wegner
meteorologist and geophysicist he was the first to propose the idea of a continental drift
What is polymorphism
minerals that have the same composition, but different internal arrangements of elements resulting in different properties
What criteria must satisfy to be classified as dwarf planets?
must orbit the sun be nearly spherical in shape cannot orbit another planet are not large enough to sweep their orbits clear of debris
Satellite planets
orbits that orbit other planets as well as the sun
Which two elements are dominant in the crust (upper ~30 miles below Earth's surface)
oxygen and silicon
What two elements are found in all magma
silicon and oxygen
Covalent bond
some electrons are shared between elements
Who was James Hutton
the father of modern geology
What determines atomic number?
the number of protons in the nucleus of an atom
How is the atomic weight (or mass number) determined?
the number of protons plus the number of neutrons
What are radioactivity/radioactive decay?
the process in which nuclei spontaneously break apart or decay
Daughter isotope
the result after protons and/or neutrons have been gained/lost from the Parent isotope
Half life
the time required for half of the nuclei in a sample to decay
Why do some isotopes decay radioactively
they have an unstable nucleus which means that the bonding forces in the nucleus are too weak to hold protons and neutrons together
what are meteoroids
very small asteroids
What are comets
"dirty snowballs" they're frozen gases that surround a rocky and/or metallic mineral
terrestrial planets
"the interior" planets Mercury, Venus, Earth, and Mars small, dense, made of heavier particles, more rocky, have atmosphere (except for mars' which has pretty much burned away)
How did Earth's moon form?
4.6 billion years ago a "mars sized object" hit Earth and the debris from that impact resulting in the formation of the moon
What is the suggested age of our solar system?
4.7 billion years
What is the nebular theory?
4.7 billion years ago Nebula of H, He, and stardust was pulled down by gravity and formed into a rotating disc it formed a protosun; heavier material stays closer to it and lighter material is flung farther away planetesimals form during collision of other materials hot, magma rich planets chemically differentiate and produce the earth's layer structure
What was the estimated age of the earth during the time when Catastrophism reigned
6,000 yrs old
How many planets are in the solar system?
8
What is a hypothesis? What is a theory? What is the difference between them?
A hypothesis is a "tentative explanation" or an educated guess. A theory is a hypothesis that has been tested and proven true. The difference is a hypothesis has not been tested.
What's a lightyear
A light year is the distance it takes to travel in one year 186,000 miles/second
What are the three types of decay discussed in class
Alpha Emission Beta Emission Electron capture
Who were some of the first persons to study earth processes and describe them?
Aristotle - observed fossils in rocks. Concluded natural processes tend to be slow and cannot be observed within a person's lifetime. Theophrastus - wrote the first book on minerals
Alpha Emission
Atomic Number decreased by 2 Mass Number decreased by 4
What is the goal of science and scientific studies
Because the world is consistent and predictable, the goal is to find natural explanations for natural processes; Also to be able to find patterns and predict future events.
What is Catastrophism?
Catastrophism is the belief that the Earth's landscapes had been shaped primarily by great catastrophes.
continental drift
Continental drift idea states one supercontinent that consisted of all the Earth's landmasses once existed and then began to fragment into smaller landmasses.
K-T boundary
Cretaceous-Teritary The K-T boundary marks the end of the era in which dinos and other reptiles dominated the landscape and the beginning of the era when mammals dominated the earth. It's important because ¾ of all plant and animals species died in a mass extinction.
What do elements bond
Electrons have a negative charge that offsets the positive charge of protons in the nucleus
What is meant by electron shell? How many electrons fit on each shell?
Electrons orbit the nucleus in a shell 1st shell holds 2; the 2nd and 3rd shells each hold 8
How did other elements in the periodic table form?
Fusion Hydrogen and helium further combine to create new elements Supernovas (stardusts) creates the rest of the elements
What is geology?
Geology is the study of the earth.
What did Leonardo DaVinci contribute to geology?
He noted that rivers carry material (sediment) to the ocean where the material is layed down and converted to rock (sedimentary rock) and ultimately uplifted to make mountains. Agreed with Aristotle that fossils were once living organisms that died and were preserved in rock.
What two elements formed right after the "Big Bang"?
Hydrogen and Helium
What is the "Principle of Parsimony" or "Ockham's Razor"?
If more than one hypothesis exist to explain a natural phenomenon, the one that uses the fewest assumptions is most likely correct.
What are the three main rock groups?
Igneous Metamorphic Sedimentary
What are the basic characteristics of a mineral
Inorganic solid naturally-occuring definite chemical composition that varies within very narrow limits orderly internal structure that gives distinct physical properties
What are the two kinds of igneous rocks? Where do they form?
Intrusive/plutonic (form is magma) Extrusive (forms in lava)
What kinds of meteoroids exist?
Iron, Stony (Chondrite), and Stony-Iron
Why are some important reasons to understand geology?
It's our habitat Human Resources To be aware of threats i.e. earthquakes and volcanoes Pollution
Who proposed the idea of catastrophism
James Ussher
Jovian Planets
Jupiter, Saturn, Uranus, Neptune large, less dense, gaseous
What is the difference between magma and lava
Lava is magma that erupts at Earth's surface
What is their order from the sun outward?
Mercury Venus Earth Mars Jupiter Saturn Uranus Nachos
What catastrophic event is related to the K-T boundary
Meteorite impact 65 million years ago in the Yucatan peninsula - proposed by Luis and Walter Alvarez
What's the difference between and meteorodis and a meteorite
Meteoroids never enter Earth's atmosphere
Beta Emission
Neutron is converted to proton in the new daughter nucleus Atomic # is increased by 1 Mass number does not change
What elements are contained in the silicate mineral group
Oxygen, Silicon, Aluminum, Iron, Calcium, Sodium, Potassium, Magnesium
Electron capture
Proton is converted to neutron atomic # is decreased by 1 Mass number does not change
Which mineral group makes up most of the crust
Silicates
Dwarf planets
Small round bodies that orbit the sun but have not cleared the area around their orbits of other orbiting bodies
Stable vs. Unstable isotopes
Stable isotopes do not change over time; unstable isotopes and usually result in the formation of different elements
What is the "Big Bang" theory
The formation of the universe theory A big explosion created matter that led to the creation of matter that formed the galaxy and then the elements synthesized into a super nova
Uniformitarianism
Uniformitarianism is the principle that states the physical, chemical, and biological laws that operate today have also operated in the geological past. o "the present is the key to the past" o processes that happen today, have happened in the past in the same way.
How much material is left after 1 half-life, 2 half-lives, 3 half-lives
1 half-life = 50% parent; 50% daughter 2 half-lives =25% parent; 75% daughter 3 half-lives = 12.5% parent; 87.5% daughter
What are the basic steps in the Scientific Method?
1. Observation 2. Hypothesis 3. Prediction (repeat hypothesis) 4. Test 5. (IF THE TEST WORKS) becomes theory
What is the suggest age of the universe according to the Big Bang Theory
13.7 billion years
Georges Cuvier
1st to propose extinctionism
According to geologists, what is the suggested age of the solar system and Earth?
4.5 billion years
How old is the earth's moon?
4.5 billion years