Geology Chapter 4 Earth Materials
What factors contribute to a water molecule having polarity?
-Hydrogen atoms are grouped on one side of the oxygen atom. -Electrons spend more time around the oxygen atom and give the molecule a negative side and two positives ends on the other side. -Oxygen more strongly attracts electrons than hydrogen does.
Nonsilicate minerals
-Include the carbonates, oxides, sulfides, sulfates, and halides. -Do not contain silicon -Include calcite, hematite, pyrite, gypsum, and halite.
Which of the following help determine the outward shape of a crystal?
-The arrangement of atoms in the crystal -How the crystal's growth was affected by the material around it
A silicone-oxygen tetrahedron _____________.
-forms a building block for the vast majority of minerals on Earth -may join with other tetrahedra or cations to form different types of silicates and a wide variety of minerals -has one silicon atom bonded with four oxygen atoms
why is the lower density of ice compared to liquid water so important?
-ice floats in water; if it didn't, lakes would freeze solid in winter as surface ice sinks to the bottom. -It aids in weathering, as water that freezes and expands can pry apart rocks and soil
Rank the following by size in order from smallest to largest, with the smallest on top.
1 Electron 2 Atomic nucleus 3 Single atom of an element 4 Mineral
Match the location with its two most common elements
Earth's Crust - Silicon and Oxygen Universe - Hydrogen and helium The entire Earth - oxygen and iron
Metals
Elements represented in this group include Na, K (alkali) and Fe, Cu (transition).
True or false: A geologist must know all of the different types of minerals in order to correctly identify and classify most rocks.
False
Of the four most abundant elements in the entire Earth, which is the most common?
Iron
Hematite
May be used for chemical components; iron is the main ingredient in steel and is mostly mined from minerals such as this.
Quartz
May be used for chemical components; the element silicon is used to create computer chips and is mostly derived from this mineral.
Gypsum
May be used for its physical properties; sheetrock and plaster products are made from this mineral.
Clays
May be used for its physical properties; this mineral is used to produce brick, cement, and ceramics.
There are more than 4,000 known minerals, most of which are ______________.
uncommon to rare
Which of the following are ways in which minerals are used for items typically found in a medicine cabinet?
- "Scouring agents" in toothpaste contain calcite -Fluoride in toothpaste is derived from fluorite -Emery boards have either garnet or corundum.
what is true about asbestos?
- Chrysotile (white) asbestos does not pose a significant health risk unless breathed in large amounts for a long time. - Amphibole (blue) asbestos poses a severe health risk
Polarity
-Attraction to ions -Dissolution of solids composed of anions and cations
Which of the following are true of the organization of rows and columns in the periodic table?
-Elements in the first column have only one electron in their outer shell -Elements in the last column are noble gases and have full outer shells -Rows indicate the number of electron shells
Silicate minerals
-Include quartz, feldspar, mica, olivine, and pyroxene. -Contain silicone-oxygen tetrahedra -Account for over 90% of the minerals in Earth's crust
Rank the following earth materials in order of their most likely occurrence, starting at Earth's surface. Think about moving from the crust to the mantle, and then to the outer and inner cores.
1 Granite and Basalt 2 Increasing amounts of olivine and pyroxene 3 Minerals stable only at very high pressures; Fe-Mg silicates and oxides 4 Molten iron with nickel and some other elements 5 Crystalline iron and iron-nickel alloy
Why are silicate minerals the most abundant in Earth's crust and mantle?
Oxygen and silicon are the most common elements in Earth's crust and are two of the most common elements in Earth's mantle.
Which of the following are attributes that are evaluated to classify crystalline and clastic rocks?
Presence/ absence of layers Crystal/ Clast shape Crystal/ Clast size Minerals Present
Which of the following best describes the materials that cover Earth's surface?
There are many different materials, and they vary by location.
Nonmetals
These elements include O and Si and typically bond with both types of metallic elements to form minerals.
Match each observation to the geologic scale at which it would be made.
Thin Section -Internal structure of mineral crystals is seen -Light passes through mineral crystals Hand specimen -Different-colored grains are present -Minerals have different colors Cliff face -Rock looks homogenous -Rock appears to be one color
Atomic Symbol
This is one or two letters representing, the name of the element.
Atomic number
This is the number of protons in the atom.
Periodic Table
This organizes all the chemical elements according to atomic number and electron orbitals.
The periodic table categorizes ___________ based on their atomic number and chemical properties.
elements
Which are true of the Periodic table?
-It includes an element's atomic symbol and atomic number -It begins with the lightest element and advances to higher atomic numbers and heavier elements from left to right and from top to bottom. -Grouped elements tend to have similar chemical properties (like the two different types of metals, the nonmetals, noble gases, etc.)
What is true of atoms, elements, and minerals?
-Minerals are composed of chemically bonded elements. -An element is a type of atom that has a specific number of protons. -An atom is the smallest unit of an element that retains the characteristics of that element.
Which of the following are common types of Cleavage (and their associated minerals/ mineral groups)?
-One direction (mica) -Three perpendicular directions (halite) -Two non-perpendicular directions (amphibole) -Two perpendicular directions (pyroxene) -Three non-perpendicular directions (calcite)
The common non silicate mineral groups include which of the following?
-Oxides -Sulfates -Halides -Carbonates -Sulfides
Hydrogen Bonding
-Surface tension -Viscosity
An unknown mineral sample is scratched by a copper wire, but not by a fingernail. Based upon the Mohs hardness scale, what is the likely identity of this mineral?
Calcite
Match the mineral/mineral group with how it is used, based on its physical properties.
Quartz - Hardness, transparency, and high silica content help make this mineral good for making glass windows and glass block. Clay - Absorbent properties allow it to be used for cat litter Feldspar - Improves hardness and durability of glass; used in ceramics, china, and glass-fiber insulation; this mineral is often mined from granite. Gypsum - This mineral, which forms through evaporation, is naturally fire-resistant; used for wallboard, plaster, and cement production.
Match the rock-forming mineral class with its description.
Silicates - The most important mineral group on Earth; contain silicon and oxygen; example is quartz. Carbonates - Carbon and oxygen bonded in a triangular arrangement; example is calcite. Oxides - Oxygen bonded with a metal; example is hematite. Halides - Contain chlorine or fluorine; example is halite Sulfates - sulfur that is only bond to oxygen; example is gypsum Sulfides - Sulfur bonded with a metal; example is pyrite Native minerals - Minerals that contain only a single element; example is copper
The ratio of density of a mineral to that of freshwater is called the mineral's _____________.
Specific gravity
Match the mineral with a common use
Talc - Baby powder (from the softest mineral) Mica - Makeup (as glitter) Clay minerals - makeup and foot powder Trona and Fluorite - toothpaste
This is the one word geologists use to describe how grains and minerals are arranged in a rock.
Texture
Magnetite and hematite occur together in layered sedimentary rocks called ___________.
banded iron formations
An ion with a positive charge is called a (n) _______________, whereas an ion with a negative charge is called a (n)_________________.
cation, anion
Over 90% of the Earth's ________ is composed of silicate minerals.
crust
Silicate minerals that are rich in magnesium and iron are _________ colored.
dark
what is the most abundant element in the universe?
hydrogen
The most common minerals in the upper part of the continental crust are __________-colored silicates. They are felsic in composition, and their color is a direct result of their elemental composition.
light
dolomite is very similar to calcite, but some of the calcium in its structure has been replaced with _________.
magnesium
A geologist who is also a mineralogist would generally study
minerals such as quartz and halite
electrons
negatively charged particles in orbit around the nucleus of an atom
atomic mass
number of positively charged plus neutrally charged particles in an atom
Nucleus
part of the atom that contains the protons and neutrons
neutrons
parts of the atom that do not have a charge
protons
parts of the atom with a positive electrical charge
water makes a good cleaning agent and solvent because it is able to dissolve materials due to its
polarity
Cations have loaned out electrons and so have a _________ charge, whereas anions have gained electrons and so have a _______ charge.
positive, negative
electron shells
the different energy states of negatively charged atomic particles arranged around the nucleus of an atom
Crystalline
Forms in high-temperature environments; minerals are interlocking.
Clastic
Forms in low-temperature environments, at or near Earth's surface.
which of the following make it difficult to represent the model of an atom?
- Atoms are much larger than their nuclei -Atoms are not hard spheres with well-defined edges -Electrons are constantly in motion and do not truly follow orbital paths -Electrons are too small to be shown to scale
Rank the following in order to show the dissolution of halite in water. Place the first event at the top and the last event at the bottom.
1 Halite crystals are immersed in water 2 The positive end of a water molecule becomes attracted to CI anions, whereas the negative end of a water molecule becomes attracted to Na cations. 3 When the attraction of the polar water molecule to various cations and anions is strong enough, it pulls the ions way from the halite crystal. 4 Na Cations become surrounded by negative sides of water molecules and Cl anions become surrounded by positive sides of water molecules. 5 As this process is repeated, the halite Crystals are eventually dissolved in water.
Rank the bond types in order of their strength, placing the weakest bond at the top and the strongest at the bottom.
1 Intermolecular force 2 Metallic bond 3 Ionic bond 4 Covalent bond
Rank the following in order to show the precipitation of halite from water. Place the first event at the top and the last event at the bottom.
1 Salty water begins to evaporate 2 As water molecules move out of the liquid state, Na cations and Cl anions become more concentrated and are left behind. 3 Na cations and Cl anions become closer to each other and begin to bond. 4 Resulting NaCl pairs combine and begin to organize into an ordered structure: a halite crystal.
Which of the following is a characteristic of crystals and/or clast that is not used in classifying a rock?
Density
Match the mineral property with how it is tested.
Hardness - Use reference minerals and other standardized materials to see which are scratched by an unknown mineral and which are not. Streak - Observe color left behind on a porcelain plate when mineral is dragged across it. Effervescence - Observe if a dilute HCI solution bubbles when placed on mineral. Magnetism - Observe if magnet sticks to mineral.
Match the silicate mineral group with its description
Independent tetrahedra - Minerals (like olivine) do not break along clearly defined planes; all bonds are almost equally strong Single chains - Tetrahedra share two O atoms and are strongly bonded; cleavage is parallel to the bonded tetrahedra Double chains - Half the tetrahedra share two O atoms and half share three; minerals cleave parallel to structure and along two planes at 60° and 120°. Sheets - Tetrahedra share three oxygen atoms; cleavage of minerals (like micas and clays) is in one main direction. Frameworks - Tetrahedra share four O atoms; quartz, with no cleavage, or feldspar with cleavage.
match the type of bond with its mineral example(s)
Ionic - Halite Covalent - Quartz and diamond Covalent and ionic - Calcite metallic - Gold and Copper covalent and intermolecular - Graphite
Noble gases
The include the elements Ar and He; these do not readily combine with other elements.
If a mineral lacks planes along which it may cleave, what will occur?
The mineral will fracture in an irregular pattern
Why is ice less dense than water?
When water freezes, the molecules arrange into a crystal form in which they are farther apart than in liquid water