8.1 Matter scientists use the word matter to describe what something is made of matter is anything that takes up space and it is what gives something its mass how much matter determines how much mass something has all matter has two types of properties:
physical properties- properties you can see with naked eye: shape, color, size, solid, liquid chemical properties- describe how a substance interacts with other substances to produce different kinds of matter
Matter is made of elements.
An element is a substance that has characteristic set of physical and chemical properties. over 90 elements that occur naturally, and another dozen or so that are man made eight element make up 98% of the Earth's crust oxygen silicon aluminum iron calcium sodium potassium magnesium
75 % of earth's crust is made up of oxygen and silicon elements are made up of atoms
the smallest unit of an element that has all of the properties of that element is an atom atoms can be broken into subatomic particles:
1. proton- has a positive charge & is found in the nucleus
2. electron- has a negative charge & is found in the electron cloud
3. neutron- has neutral or no charge & is found in the nucleus nucleus has positive charge; electron cloud has negative charge an atom of a specific element is distinguished from all other elements by its atomic number or number of protons atomic number = number of protons because an uncharged atom has no charge the number of protons equals electrons

Elements in the same column on the periodic table has similar properties; similar electron arrangements
Each atom also has a mass number which tells you how much an atom weighs mass number = # of protons + # of neutrons
8.2 Combinations of Matter
usually find elements mixed with other elements compound- two or more chemically united elements different properties than either of it's elements ex: NaCl Na= metal, silver Cl= poisonous gas, green/yellow molecule is the smallest unit of a compound that has all the properties of that compound
molecule of NaCl 4NaCl some elements exist in nature as diatomic elements
O
2
I
2 molecules made of two atoms
Energy Levels electrons are found in energy levels outside of the nucleus in the electron cloud different kinds of atoms form molecules or compounds according to how their electrons are arranged each energy level can only hold a certain number of electrons
1st- 2 e-
2nd- 8 e-
3rd- 8 e- electrons fill lower levels first, then continue to move away from the nucleus electrons in lower energy levels are held more tightly to the nucleus than those in high energy levels not all elements have a full outer energy level some have less electrons than the energy level can hold

those elements are unstable and need to gain or lose electrons to become stable; this is why they are found in compounds;' they can also share electrons to become stable some atoms transfer or share electrons than others atoms with 1, 2, or 3 outer shell electrons will give them away easily; have metallic properties metallic properties include: good conductors of heat and electricity malleable - can be hammered into thin sheets ductile- can be drawn into wires atoms with more than 4 electrons in their outer energy level they are less likely to lose, more likely to gain elements that gain electrons are typically called nonmetals poor conductors of heat and electricity not malleable or ductile
Chemical bonds- when atoms combine to make a new substance; produced by interactions between element's electrons from the outer most energy level if an element has the maximum of electrons in its outer energy level, it will not bond with anything
Ionic Bonds are between a metal and nonmetal occurs when electrons are either gained or lost when an electron is transferred the atom becomes charged; a charged atom is called an ion
-if an atom loses an electron(s) it becomes positively charged
-if an atom gains an electron(s) it becomes negatively charged
Covalent Bonds electrons are shared between two atoms form covalent compounds each covalent compound consists of only one type of molecule when atoms share electrons the positive nuclei of each type of atom attract the negative electrons from the opposite type of atom the pull between the negative and positive charges is what keeps the compound together covalent compounds melt much more easily than ionic, covalent bonds are held together by weaker forces than ionic bonds

Chemical formulas for any compound, the proportion of elements is it made up of will always be the same a chemical formula indicates what elements a compound is made up of and how many atoms of each element are in that compound a subscript is used to tell you how many of each type of element are in a compound
Mixtures elements and compounds are generally found mixed together in nature a mixture is material that contains two or more substances that are not chemically combined substances in mixture keep their properties mixtures can also be separated into their parts by physical means ex: smog- emissions mixed with oxygen solutions- a mixture in which one substance is evenly dispersed in another substance
(seawater) alloys- mixture of metals- ex: brass: mixture of copper & zinc
What is a mineral?
 a mineral is a naturally occurring, inorganic, crystalline solid
 minerals are the basic materials of the earth's crust
 You ask 4 questions to determine is something is a mineral or not
 you have to answer yes to all 4 questions for the substance to be a mineral

1st question: Is the substance inorganic?
 inorganic substance is not made up of living things

2nd question: Is does the substance occur naturally?

3rd question: Is the substance solid in crystalline form?

Does it form crystals when it solidifies?

4th questions: Does the substance have a definite chemical composition?


Kinds of Minerals
 over 3000 types of minerals, there 20 common minerals
 those twenty minerals are called rock-forming minerals
 form the rocks in the earth's crust of the 20, 10 make up 90% of the earth's crust those ten are: quartz, orthoclase, plagioclase, muscovite, biotite, calcite, dolomite,

 halite, gypsum, & ferromagnesian minerals (olivines, pyroxenes, amphiboles)
 all minerals are classified into 2 main groups based on their chemical composition silicate non silicate

Silicate Minerals all contain atoms of silicon (Si) and oxygen (O) ex; quartz contains only silicon and oxygen most common silicate are feldspars type of feldspar depends on which metal combines with the silicon and oxygen orthoclase- metal present is potassium (K) plagioclase- metal present is either sodium (Na), Calcium (Ca), or both ferromagnesian minerals minerals rich in iron (Fe) and Magnesium (Mg) ex: olivine, pyroxenes, amphibole, and biotite make 96% of the earth's crust
50% is made up of feldspars & quartz
Nonsilicate minerals
4 % of earth's crust do not contain silicon
Classified into 6 Major Groups
1. Carbonates- compounds contain a carbonate group (CO
3
)
2. Halites- compunds that consists of Chlorine (Cl) or Fluorine with Sodium, Potassium, or Calcium
3. Native Elements- elements uncombined with other elements
4. Oxides- compounds that contain oxygen and element other
5. Sulfates- compound that contain a sulfate group (SO
4
)
6. Sulfides- compounds that consist of one or more elements with sulfur
Crystalline Structure all minerals in the earth's crust have a crystalline structure each type of crystalline mineral is characterized by a specific arrangement of atoms and ions crystal- a natural solid with a definite internal pattern
Crystalline Structure of Silicate Minerals all of their crystalline structure is made up of the same basic building block
4 oxygen atoms arranged in pyramid around a central silicon atom; called a silicon-oxygen tetrahedron tetrahedra combine to form the many silicate crystalline structures
Isolated Tetrahedral Silicates & Ring Silicates
(F) combined than silicon combined this is

minerals that have isolated tetrahedra contain silicon-oxygen tetrahedra that are linked only by atoms of elements other than silicon and oxygen ring silicates form when the tetrahedra are joined into three, four, or six-sided rings by shared oxygen atoms bound together by ions
Single chain, double chain,sheet, and framework silicates. single chain silicate- each tetrahedron is bonded to two others by shared oxygen atoms most of these are called pyroxenes double chain silicates- two single chains of tetrahedra bonded together most of these are called amphiboles sheet silicates- each tetrahedron shares three oxygen atoms with other tetrahedra, the 4th oxygen bonds with an atom of potassium or aluminum, which joins one sheet to another micas are an example of this framework silicates- each tetrahedron is bonded to four neighboring tetrahedra
Identifying Minerals earth scientists that study minerals are called mineralogists
Characteristics
Color some minerals have very distinct colors its generally not reliable to use color when identifying a mineral
Luster if you are going to study the color, be sure to use a freshly exposed sample surface light reflected from the surface of a mineral metallic luster- reflects light like a polished a metal any mineral that doesn't reflect light like a polished metal is considered to have a nonmetallic luster glassy luster- transparent minerals & other minerals that look like waxy luster- minerals with appearance of candle wax glass pearly luster- minerals with appearance of a pearl brilliant luster- minerals that shine like diamond
Streak earth (dull) luster- minerals that lack shine completely more reliable clue as to what a mineral is than color streak is the mineral in powdered form it may not be the same color as the solid piece of mineral was metallic minerals tend to have dark streak nonmetallic minerals tend to have very light streak, typically are shades of the color that the mineral appears to be
Cleavage & Fracture lighter

Minerals tend to split easily along certain flat surfaces, this is called
Cleavage is related to the types of bonds in the internal structure of the mineral the surface where cleavage happens runs parallel to a plane in the where bonding is weak not all minerals have cleavage planes, some just fracture when a mineral fractures it breaks, unevenly, curved, or into irregular pieces
fracture can be described in different ways, it is described according to its appearance rough surface- irregular or uneven fracture if it looks like a piece splintered wood- splintery or fibrous fracture curved surfaces- conchoidal fracture
Hardness the measure of the ability of a mineral to resist scratching cleavage crystal the hardness of a mineral can be determined by scratching it against the minerals on Mohs hardness scale to test an unknown mineral for hardness, you must determine which hardest mineral on the scale that it can scratch the hardness of a mineral is largely determined by the strength of bonds between the atoms or ions that make up its internal
Crystal Shape is the the structure mineral crystals will form in one of six shapes each kind of mineral in characterized by crystals of specific shape a certain mineral will always have the same shape
Six Basic Crystal Shapes
Isometric or Cubic System three axes of equal length intersect at 90 degree angles. ex: galena, halite, and pyrite
Orthorhombic System three axes of unequal length intersect at 90 degree angles ex: olivine, topaz, and staurolite
Triclinic System three axes of unequal length are oblique, to one another
Monoclinic System
Three axes of unequal length, two intersect at 90 degree angles. The third axis is oblique to the others.
Ex: micas, gypsum, augite
Hexagonal System
Three horizontal axes of the same length that intersect at 120 degree angles. The vertical axis is longer or shorter than the horizontal axes. ex; calcite, hematite, and quartz
Tetragonal System
Three axes intersect at 90 degree angles. The two horiztonal axes are the same length.
The vertical axis in longer or shorter than horizontal axes.

Density ex: cassiterite, zircon ratio of mass of a substance to its volume grams per centimeter cubed
D = m/v
D density m mass v volume the density depends kind of atoms the substance is made out of density helps identify heavier minerals more readily than lighter minerals
Special Properties of Minerals
Magnetism most common magnetic mineral is called magnetite lodestone is a mineral that acts as a magnet
Fluorescence & Phosphorescence fluorescence is the ability of something to glow under ultraviolet fluorescent minerals absorb ultraviolet light and then produces light of various colors phophorescence is the ability of something to store ultraviolet light glow after the light is shut off
Double Refraction light rays bend as they pass through transparent minerals, this is refraction double refraction occurs when light is bent in such a way that two are produced crystal occurs because light is split into two parts as it enters the light visible and called images