From Atoms To Minerals

Question 0

Protons

Answer 0

Have positive charge and their number in the nucleus defines an element

Question 1

What is an atom

Answer 1

A basic unit of matter that consists of a central nucleus surrounded by a cloud of electrons

• nucleus
• protons
• neutrons
• electron orbital shells

Question 2

Neutrons

Answer 2

Are electrically neutral but a large number of them can make nucleus unstable so it decays radioactively

Question 3

Electrons

Answer 3

Have negative charge, they can be shared with neighboring atoms to produce bonds

Question 4

What is an element

Answer 4

An atom of a given element has specific properties that can differentiate its behavior in nature from atoms of other elements
-an element is defined by the number of protons in the nucleus of its atoms

Question 5

Bohr’s model of an atom

Answer 5

• electrons orbit nucleus in discreet energy shells and sub-shells
• addition of electrons into a new shell defines a new row in periodic table
• atom favors an even amount of electrons, Na gives away an electron to become + charged cation, Cl gains an electron to become - charged anion

Question 6

Ions and valence

Answer 6

• ion is charged atom
• valence is the charge that an atom has when bonded
• for example: silicon is always +4 in minerals
• for example: oxygen is always -2 in minerals
• some elements can have variable valance, for example: Fe^3+ and Fe^2+

Question 7

Ionic bonding

Answer 7

Electron almost completely “moves” from an atom to its neighboring atom as in NaCl

Question 8

Covalent bonding

Answer 8

Electrons are shared by two atoms as in O^2

Question 9

Metallic bonding

Answer 9

Electrons hop from one atom to the next as in Cu metal

Question 10

Anionic groups

Answer 10

Sometimes in nature, different elements tend to be strongly bonded together to form an Anionic group

• SiO4^4-
• SO4^2-
• CO3^2-

Question 11

Minerals

Answer 11

A mineral is a naturally occurring inorganic solid, with a regular internal crystal structure, formed by inorganic or organic processes

Question 12

Polymorphs

Answer 12

Different minerals, that have different structure, that have the same chemical composition
-polymorphs reflect different temperature and/or pressure conditions of crystallization

Question 13

Major environmentally important mineral groups

Answer 13

• mineral groups are defined on the basis of the principal anion or Anionic group, except for the native element group
• each mineral group tends to have a distinct genesis, behavior, and use

Question 14

Native elements

Answer 14

Diamond C, Graphite C, Copper Cu, Gold Au, Silver Ag

-some uses: jewelry, electrical conductors, insulators, abrasives

Question 15

Halides

Answer 15

• anions are halogens, including F-, Cl-
• examples: halite NaCl, sylvite KCl, fluorite CaF2
• some uses: salts, electronics, chemical industry, precipitate in salty water

Question 16

Oxides

Answer 16

• anion is oxygen (O^2-)
• examples: hematite Fe3O4, rutile TiO2
• some uses: metallurgy, electronics, pigments, ceramics

Question 17

Hydroxides

Answer 17

• Anionic group is hydroxyl (OH-)
• examples: geothite FeOOH, gibbsite Al(OH)3
• clays are hydroxides
• some uses: gibbsite is a major source for aluminum, ceramics

Question 18

Sulfides (S2-)

Answer 18

• anion is sulfur S2-
• examples: pyrite FeS2, Galena PbS
• commonly make ores of important metals, including copper lead and zinc

Question 19

Sulfates

Answer 19

Anionic group is sulfate SO4^2

• examples: gypsum CaSO4H2O, barite BaSO4
• include mostly alkali earth elements bonded with sulfate
• usually form evaporates by evaporation of salty water

Question 20

Carbonates

Answer 20

Anionic group is carbonate CO3^2-

• examples: calcite CaCO3, dolomite MgCa(CO3)2
• precipitate in warm ocean water
• important in the carbon cycle
• most caves occur in carbonates
• some uses: building industry chemical industry

Question 21

Phosphates

Answer 21

Anionic group is phosphate PO4^3-
Example: apatite Ca5(PO4)3(OH,F)
-bones are biogenetic phosphates
-some uses: fertilizers

Question 22

Silicates

Answer 22

Anionic group is silicate (SiO4^4-)

• examples: Quartz SiO2
• some uses: glass, ceramics, electronics, abrasives, food

Question 23

Silica tetrahedron

Answer 23

The basic building block of silicates

-can be stacked in several different arrangements with other cations in between