2.1 Matter 2.2 Minerals 2.3 Properties of Minerals

 An element is a substance that cannot be broken down into simpler substances by chemical or physical means ◦ Example-anything on the periodic table (oxygen, gold, sulfur etc.)  An atom is the smallest particle of matter that contains the characteristics of an element ◦ An atom is composed of  Nucleus at the center  Protons(+) and Neutrons  Around the Nucleus are Electrons (-)

 The number of protons in the nucleus of an atom is called the Atomic Number ◦ Element is distinguished by the Atomic number  Electrons are located in regions called Energy Levels  Atoms with the same number of protons but different numbers of neutrons are isotopes of an element  The Mass number of an atom is the total mass of an atom (protons plus neutrons

 Chemical combinations of the atoms of elements are called Compounds  When an atom’s outermost energy level does not contain the maximum number of electrons, the atom is likely to form a chemical bond with one or more other atoms

 An atom that has an electrical charge because of a gain or loss of one or more electron is called an Ion ◦ Ionic bonds form between positive and negative ions (Strong Bonds)  Covalent bonds form when atoms share electrons  Metallic bonds form when electrons are shared by metal metals

 Pg 43 (1-5)  Don’t fall behind

 Characteristics of a mineral  1) Naturally occurring  2) Solid Substance  3) Orderly Crystalline structure- atoms are arranged in an orderly and repetitive manner  4)Definite chemical composition- most are compounds of multiple elements (except gold and silver)  5) Generally considered inorganic- Does not contain carbon (other than from living creatures, shells, bones, corals reefs)

 The major processes by which minerals form  1) Crystallization from Magma- As magma cools, elements combine to form minerals  2) Precipitation- When a solid forms from a liquid (Water evaporates and salt crystals form) 3) Pressure and Temperature- coal turning into a diamond  4)Hydrothermal Solutions- Hot water and dissolved substances creates new minerals

 Mineral Groups  Silicates- Silicon and oxygen. Most form in mountains which show geological history, most common silicate is Quartz  Carbonates- 2 nd most common mineral group on Earth, contains Carbon, Oxygen and a metallic element. (limestone, marble)  Oxides- Minerals that contain oxygen and one or more other elements normally a metal

 Sulfates and Sulfides- Minerals containing Sulfur  Halides- Minerals containing Halides or elements in Group 7A  Native Elements- Elements in their pure form, Gold, Silver, Copper, Sulfur, and Carbon

 Small amounts of different elements can give the same mineral different Colors  Streak is the color of a mineral in its powdered form- Will not vary like color  Luster is used to describe how light is reflected from the surface of a mineral

 Crystal Form is the visible expression of a mineral’s internal arrangement of atoms  Every mineral has a different type  Hardness is a measure of the resistance of a mineral to being scratched ◦ Arranged on the Mohs scale from 10 (hardest) to 1 (softest)  Cleavage is the tendency of a mineral to cleave, or break along flat, even surfaces.

 Minerals that do not show cleavage when broken are said to Fracture  Density is a property of all matter that is the ratio of an object’s mass to its volume  Other minerals can be recognized by other distinctive properties

 Pg 55 (1-5)  NEVER COULD HAVE HAPPENED WITHOUT MINERAL CRYSTALS