Exam 1 - Minerals to Mining

Question 1

Test

What is all matter made of?

test

Test

Answer 1

All matter is made up of atoms, and atoms are made up of atomic particles (electrons, protons, and neutrons

why

why

Question 2

describe an atom

Answer 2

the smallest unit of a chemical element

Atoms have a nucleus composed of neutrons and protons and has a positive charge

Negatively charged electrons orbit around the nucleus in shell-like layers

Question 3

describe a chemical element and its component parts

Answer 3

pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus

Elements have equal balance in numbers of positively charged protons and negatively charged electrons. Common examples of elements are iron, copper, silver, gold, hydrogen, carbon, nitrogen, and oxygen

Question 4

name an defining characteristic of an element

Answer 4

An element is a substance that cannot be broken down into simpler substances by chemical means

Question 5

what is an element composed of?

Answer 5

An element is composed of atoms that have the same atomic number, that is, each atom has the same number of protons in its nucleus as all other atoms of that element

Each element is assigned a 1-2 letter symbol to represent the element for general use, such as in the writing of chemical formulas (such as H2O used for water)

Question 6

describe the periodic table of elements

Answer 6

a list of known chemical elements arranged in order by atomic number from smallest to largest and by group chemical properties

108 known elements - 92 are naturally occurring elements (prior to development of artificial nuclear research and development)

The lightest element, hydrogen, has one proton, whereas the heaviest naturally occurring element, uranium, has 92 protons. In general elements on the left side of the periodic table are elements classed metals (highlighted in gray, green, yellow, and pink), and elements on the right (shown in blue) are nonmetals. On the far right in orange are a group of elements know as noble gases.

Question 7

describe a molecule

Answer 7

Atoms bond together to form molecules. A molecule is a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction

For instance, a molecule of water—chemical formula, H2O —is made up of two hydrogen atoms and one oxygen atom

Question 8

chemical substance

Answer 8

A chemical substance is a form of matter having constant chemical composition and characteristic properties

Question 9

describe a chemical compound

Answer 9

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions

Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together in a defined spatial arrangement by chemical bonds. All minerals are chemical compounds, but by comparison relatively few compounds are naturally occurring minerals!

Question 10

types of chemical bonds

Answer 10

minerals are chemical compounds, but by comparison relatively few compounds are naturally occurring minerals

Question 11

describe a chemical mixture

Answer 11

A mixture is a combination of two or more pure substances in which each pure substance retains its individual chemical properties. Examples of mixtures include rocks, magma (molten rock) air, and seawater

Question 12

chemical formulas

Answer 12

Chemical formulas are used to describe compounds such as H2O (for water), NaCl (for salt), CO2 (for carbon dioxide)

Chemical formulas may be simple text designations showing the ratio of elements, or may be represented by graphic means showing relationships (orientation and bonding) between elements within molecules

Question 13

chemical bonds

Answer 13

Molecular compounds are held together on an atomic level by chemical bonds

Chemical bonds are persistent forces of attraction between atoms or molecule caused by electrostatic forces (positive or negative charges) or the sharing of electrons between bonded atoms.

Question 14

what are the three types of chemical bonds?

Answer 14

ionic bonds, metallic bonds, and covalent bonds

The types of chemical bond influence the physical properties of the molecular compounds they form.

Question 15

ionic bonds

Answer 15

Molecular compounds held together by ionic bonds are salts. An ionic bond is a chemical bond between two oppositely charged ions

Typically, metals lose valence electrons (loose electrons in their outer shell of orbiting electrons) to become positively charged cations, whereas the nonmetal accepts electrons to become negatively charged anions.

For example, common salt (NaCl) has ionic bonds between sodium (Na+) has a positive charge and chlorine (Cl-) has a negative charge. Salts readily dissolve in water as their charged ions are attracted to parts of water molecules that can also have positive and negative charges. As water evaporates, the ions dissolved in water will precipitate again as salts (Figures 2-6 and 2-7). Natural salts like halite (NaCl) and gypsum (CaSO4) are generally soft minerals and can dissolve in water.

Question 16

metallic bonds

Answer 16

Metals are held together by metallic bonds

Compounds with metallic bonds transmit electricity

With metallic bonds, the electrons disassociate from orbiting a single atom and become more of a cloud electrons that surround the positively charged nuclei of interacting metallic ions. Metalloids are intermediate between those of metals and solid nonmetals. Although most elements are metals (all those on the left and center parts of the Periodic Table), only a few elements occur naturally in metallic form including gold, platinum, copper, iron, and mercury (in liquid form).

Question 17

covalent bonding

Answer 17

Molecular compounds held together by covalent bonds are non-metallic compounds

Covalent bonds occur when two or more atoms share orbiting electrons; sharing of electrons, NOT transfer like ionic bonds

visualize overlapping valence shells of electrons

MUCH stronger than ionic bonded minerals

Question 18

Van der Waals Force

Answer 18

Van der Waals forces (bonds) are weak, nonspecific forces between molecules and include attractions and repulsions between atoms, molecules, and surfaces.

Van der Waals forces are responsible for friction and what makes water sticky.

Question 19

mass in chemistry

Answer 19

Mass is the property of matter that measures its resistance to acceleration

Roughly, the mass of an object is a measure of the number of atoms within it.

Mass is often confused with weight. Weight is a measure of an amount of mass under the influence of gravity. For instance, a 150 pound person on Earth would only weigh 25 pounds on the Moon because the Moon only has 1/6 the gravity of Earth.

Density is the ratio between mass and volume. It is a measure of how much matter an object has in a unit volume (such as cubic meter or cubic centimeter).

Question 20

density

Answer 20

density = mass/volume

Usually defined in grams per cubic centimeter - gm/cm3

Question 21

what are the most abundant elements found in Earth’s natural environment?

Answer 21

The most abundant elements in our physical environment are: H, C, N, O, Na, Mg, Al, Si, P, S, Cl, K, Ca, Fe. In chronological order by atomic number, these symbols are H hydrogen, C carbon, N nitrogen, O oxygen, Na sodium, Mg magnesium, Al aluminum, Si silicon, P phosphorus, S sulfur, Cl chlorine, K potassium, Ca calcium, and Fe iron.

These elements are:

• ingredients of common minerals, rocks, sediments, and soil (solids)
• components of seawater and air (liquids & gases)
• essential nutrients for life (organic compounds).

Question 22

what are the most common elements in the earth’s crust?

Answer 22

oxygen and silicon are the two most abundant elements in Earth’s crust

compounds that contain some silicon and oxygen are the most abundant in rocks in the Earth’s crust. These compounds occur as common silicate minerals that occur in abundance wherever rocks of certain origins occur on the surface

Question 23

minerals

Answer 23

• naturally occurring
• inorganic (never living)
• solid with a definite internal arrangement of atoms (crystal structure)
• has to have a chemical formula that only varies over a limited range that does not alter the crystal structure
• The crystal structure of a mineral has a definite chemical composition

Question 24

rock/stone

Answer 24

• relatively hard
• naturally formed aggregate of mineral one or more minerals
• Rocks are mixtures and may consist of one or more minerals, but may include organic matter and other non-mineral substances, such as gases and water
• makes up the materials of the solid Earth and other rocky planets and moons in the Solar System

Question 25

what does the mineral composition of rock reflect?

Answer 25

The mineral composition of a rock reflects the physical environment and geologic history where a rock formed

Question 26

the rock cycle

Answer 26

a graphic and conceptual model used to illustrate common rocks and earth materials and the processes that form or change in the Earth’s crust over time

The rock cycle depicts the series of events in which a rock of one type is converted to one or more other types and then back to the original type (see the general classification of earth materials below)

Both products (rocks and sediments) and processes (such as melting, cooling, erosion, deposition, metamorphism, remelting) are part of this idealized cycle

The passage of geologic time is the essential component, although some processes are much faster than others.

Question 27

igneous rock

Answer 27

The term igneous applies to rocks or minerals that solidified (crystallized) from molten or partly molten material—referring to magma (molten material underground), or lava (molten material on the surface of a volcano)

The word igneous also applies to the processes related to the formation of such rocks. (Igneous rocks and volcanism are the focus

Question 28

sedimentary rock

Answer 28

The term sedimentary applies to materials consisting of sediments or formed by deposition

The word sedimentary applies to both the processes and the products of deposition. Sedimentary rocks form from sediments

Question 29

halite (NaCl): salt

Answer 29

halite (or common table salt, NaCl) which consists of two elements sodium (Na) and chlorine (Cl) that when combined in a repeating arrangement in a crystalline structure

Note that it would take 4 NaCl molecules (4 sodium atom and 4 chlorine atoms) to make of the minimum cubic unit cell representing the crystal structure of halite. The arrangement of atoms in a cubic structure of the mineral, halite, is repeatable whether on an atomic scale or a microscopic scale (as in table salt) or macroscopic (fist-sized chunk)

Question 30

carbonate minerals

Answer 30

Carbonate minerals have carbonate ions (-1CO3) within their mineral structure. In nature, most carbonate minerals form from the interactions of carbon dioxide and metals dissolved in water

The mineral calcite is perhaps the most amazing mineral. It has many crystalline forms and can form in many geologic settings. It is also an exceeding important mineral resource - it is used in the manufacture of cement, and is used in some manner in the process of manufacturing of thousands of compounds used in industry, including the manufacture of steel and the production of medicines and food. Calcite consists of a crystalline structure composed of molecules of calcium carbonate (CaCO3). Basically, the calcium (Ca) comes from the Earth, and the CO3 comes from the atmosphere, and nearly all the CaCO3 is deposited by biological activity in the oceans and precipitated from water underground.

Question 31

dolostone and limestone

Answer 31

Calcite is the dominant mineral in the sedimentary rock called limestone. Over time, groundwater rich in dissolved magnesium can seep through limestone, gradually converting calcite to dolomite. As a result, ancient limestone rock formations often contain higher concentrations of dolomite than calcite. If a rock has more that 50 percent dolomite it is called dolostone

Question 32

observable properties of a mineral

Answer 32

crystal form - 
color 
cleavage
luster (metallic, non-metallic)
diaphaneity (transparent, translucent or opaque) 
double refraction 
striations 
feel 
odor (smell) 
taste

Question 33

Crystal form

Answer 33

many minerals have unique and sometimes obvious crystal structures, however, crystal structure alone may not be enough to identify a mineral

the external expression of the ordered internal arrangement of atoms

Question 34

color

Answer 34

some minerals have very distinct colors, however, color is not a reliable indicator by itself

E.g.1 many different minscan be brownE.g.2 single min, like quartz can be many colors

Question 35

cleavage

Answer 35

the tendency of a crystallized substance to split along definite crystalline planes, yielding smooth surfaces

Mica, feldspar, calcite, and selenite gypsum have good mineral cleavage. Flat, smooth, shiny and reflective surfaces on specimens may be either crystal surfaces and/or cleavage

Question 36

luster

Answer 36

the description of the quality and intensity (sheen or shine) of light reflected off of a mineral, particularly a reflective appearance of the exterior of crystal surfaces and cleavage planes. There are many kinds of luster

how light reflects off of an object

Question 37

feel

Answer 37

The feel of a rock is not a reliable method of testing minerals, however certain minerals have textures like “soft, silky, satin, smooth, hard, heavy or light” - but these characteristics are poorly definable as a reliable means for identifying minerals

Question 38

odor

Answer 38

few minerals have an odor. Sulfur-bearing minerals may put off a rotten-egg like smell. Many rocks of sedimentary origin have the smell of petroleum.

Question 39

taste

Answer 39

halite tastes like salt (because it is NaCl). (Note that tasting minerals and rocks is generally not recommended! Some minerals can be quite poisonous)

Question 40

hardness

Answer 40

minerals have different durability properties. Depending on mineral chemistry and crystal structure, minerals have varying degrees of hardness

measure of resistance to abrasion (Moh’s Hardnes)

minerals held together by ionic bonds (like halite, gypsum, and calcite) tend to be softer than minerals

Question 41

magnetism

Answer 41

iron (the natural mineral iron in crystalline form) and magnetite (Fe3O4) are common magnetic rocks, iron-rich meteorites are also magnetic. Figure 2-71 is sample of Diablo Canyon (Arizona) iron meteorite that is highly magnetic.

Many minerals rich in iron are partly magnetic and display measurable magnetic susceptibility that can be useful for geophysical exploration. Large bodies of rock containing iron-rich minerals can be remotely detected below the earth surface, and may be useful for detecting hidden faults, water-filled sedimentary basins, or potentially economically valuable mineral resource deposits. Magnetic susceptibility measurement are used in regional geophysical mapping.

Question 42

specific gravity

Answer 42

a measure of the density of a mineral. Specific gravity is the ratio of the density of a substance to the density of water

Tests for specific gravity require some laboratory equipment. Specific gravity is a measure of weight with a known volume

Question 43

streak

Answer 43

color of min when powdered

streak varies less than color, so it is a “better” property

Usually’ metallic mins have dark streaks

Be aware that streak tests can be destructive to mineral samples. The mineral graphite (used in pencils) leaves a black streak

Question 44

acidic reaction

Answer 44

Calcite fizzes when exposed to mild acid, releasing carbon dioxide gas. Dolomite will fizz in hot acid.

Note that all minerals are chemicals that can react to chemical agents, altering or destroying them. Whereas gemstones are typically durable, the can be susceptible to chemicals added to cleaning fluids

Question 45

atomic weight

Answer 45

of protons + # of neutrons

Question 46

fracture

Answer 46

the absence of cleavage

Question 47

how many minerals are there?

Answer 47

About 4000

40 to 50 new ones named each year

Average University Mineralogy class learns about 300, BUT…

Only about 40-50 rock-forming minerals are common in Earth’s crust

Question 48

All matter is made up of atoms, and atoms are made up of atomic particles (electrons, protons, and neutrons

why

why

Answer 48

Test

What is all matter made of?

test

Test