normal matter is composed of……. atom… · normal matter is composed of… ... minerals are a...
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Normal Matter is composed of…….
Atoms differ in the number of “pieces” ( Protons, Neutrons and Electrons) that they have inside of them.
Atoms with certain consistent characteristics are called….
matter that is made up of atoms…matter that is made up of atoms (or one atom) that have the same number of Protons in their nucleus.
What is Matter?
• Anything that has mass and volume is matter.
– Mass - is the measure of the amount of material in an object or substance.
– Volume – is the amount of space taken up by an object or substance.
• Matter is composed of elements – a substance that cannot be broken into simpler substances by ordinary chemical means (Ex. Oxygen, carbon, etc)
– Made up of tiny particles called atoms (the smallest part of an element that has all the element’s properties).
Structure of Atoms• smallest part of an element that has all the element’s
properties.
• Electrons (-) create cloud of negative charge around nucleus
• Nucleus consists of protons (+) and neutrons (0)
Structure of Atom• Atomic # - the number of protons in
the nucleus. (also equal to # electrons in the atom’s electron cloud).
– Electron cloud has Energy Levels (or layers of electrons)
• Each energy level can hold a different amount of electrons.
• Electron cloud can only have 7 Energy Levels at the most
• Atoms want to be stable – this is achieved when their outer most Energy Level is filled with electrons.
Structure of Atom
• Atomic Mass - # of protons and neutrons
– Can subtract atomic mass from atomic # to get # of neutrons (14-7=7 neutrons)
Atomic mass
But!!!Not all atoms of the same element are the same, either.
Atoms of the same element that have different numbers of neutrons
in their nuclei are called….
Notice the different # of neutrons in each Hydrogen Isotope
Certain isotopes of elements are unstable, or radioactive.
(example: Carbon-14 and Uranium-238)
These radioactive isotopes of elements allow us to do absolute-age dating!
How do Atoms Bond??
• Atoms want to be stable, so they will gain, lose, or share electrons
– Gaining, losing, or sharing of electrons forms a chemical bond that holds them together.
– There are 3 main types of Bonds:
• Covalent Bond
• Ionic Bond
• Metallic Bond
Types of BondsCovalent Bond
• Formed when atoms share electrons
– 2 or more atoms held together by covalent bonds forms a molecule.
• Ex.) in a molecule of water - two atoms of hydrogen
and one atom of oxygen share electrons. H2O
Sharing of electrons
Sharing of electrons
Types of BondsIonic Bond
• Formed by electrical attraction between atoms that have lost or gained electrons.
– Ex.) Table Salt (NaCl) – positively charged sodium ions are bonded with negatively charged chlorine ions.
– Ion – an electrically charged atom (positively or negatively charged).
• Atoms that gain electrons are negatively charged.
• Atoms that lose electrons are positively charged.
Types of BondsMetallic Bond
• Bonds are formed between metal atoms
– Electrons are moving freely all around the positive ions = sea of electrons – this allows metals to be conductive.
– Metal – an element that loses electrons easily to form positive ions
• Ex.) aluminum, sodium, calcium, zinc, gold, silver, iron
– Nonmetal – an element that gains electrons easily to form a negative ion.
• Ex.) nitrogen, oxygen, chlorine, phosphorus, sulfur
Most substances on Earth are not pure elements but rather….
???
What is a Compound?
A Compound is…..
A substance made from two or more different
elements that have been chemically
combined.
Compounds
• Can have properties unlike the elements which they are made of
• Can only be separated by chemical means
– Ex. Water molecules can be broken into hydrogen and oxygen by breaking the chemical bonds with strong electrical current.
WATER -Compound of hydrogen and oxygen
TABLE SALT -Compound of sodium and chloride
A Mixture, on the other hand, is…
A substance made from two or more different elements that have not been chemically combined, and which can be separated by physical means
Mixture
• Elements keep their own properties
• Most can be separated
– Ex. Salt water can be separated by boiling/evaporating water, salt is left behind.
Elements by themselves are called Native
Elements, they are much less common than
Compounds, because they tend to combine
with each other to form Compounds.
Elements and Compounds in their solid form make up…
A Mineral is a naturally occurring Inorganic Solid with a definite chemical composition and a
crystalline structure.
That means that…
•It can’t be organic in origin•It can’t be a liquidand..•It has to have a crystal structure
Lets put that in a list format.(** Remember…. ISODA**)
1. Minerals are a naturally occurring substance.
2. Minerals are solids.3. Minerals have a definite chemical
composition.4. Minerals have atoms that are arranged in
an orderly pattern.5. Minerals are inorganic. (They were never
alive.)
How many different minerals are there on Earth???
Answer: About 4,000
Most Common Elements on Earth’s Crust
Name Element Symbol % by Mass
Oxygen O 46.6%
Silicon Si 27.7%
Aluminum Al 8.1%
Iron Fe 5%
Calcium Ca 3.6%
Sodium Na 2.8%
Potassium K 2.6%
Magnesium Mg 2.1%
About 90% of all of the minerals in the Earth’s Crust are made up of compounds containing Silicon
and Oxygen, the two most abundant elements on Earth.
• Few minerals consist of a single element –those are called Native Elements– Ex.) Silver (Ag), Copper (Cu), Sulfur (S), Gold (Au),
Diamond (C)
• Most minerals are compounds• Ex.) Quartz (SiO2), Galena (PbS), Pyrite (FeS2),
Halite (NaCl)
• Mixtures of minerals make up ROCKS!
How do Minerals Form??
1. Form out of molten rock (MAGMA)!!
2. Form from Evaporation
3. Form when existing minerals are transformed by heat, pressure, or chemical actions.
How do Minerals Form???
1. Minerals form in cooling magma chambers• As magma cools atoms, molecules, and ions move closer together and form chemical bonds that create compounds.• Types of minerals that form depend on the types and amounts elements present in the magma.• Rate at which magma cools determines the size of the mineral grains (crystals).
Different types of minerals crystallize at different temperatures
Decreasing temperature
Mineral formation in a Magma Chamber
Bowen’s Reaction Series
2. Some types of minerals form as water containing dissolved ions slowly
evaporates.
- As water slowly evaporates the Na and Cl ions
bond to form the Halite mineralSalt deposits
3. Metamorphic Minerals:Some minerals occur as the result of Recrystallization and Reaction
within existing rocks which produces new minerals in response
to changes in
and
How long does it take for minerals to form??
• Minerals in solution in water can form relatively quickly when the water evaporates.
• Minerals in magma can form as quickly as the magma/lava can crystallize (lava can cool in minutes, while magma can take thousands of years).
A Crystal is….
A regular geometric solid with smooth surfaces called….
The orderly arrangement of ions, molecules, or atoms, in any
mineral determines the shape of its crystals.
Although there are thousands of different types of minerals, their crystals come in six basic types of
shapes
Silica Tetrahedron• Consists of 4 Oxygen atoms packed
closely around a Silicon atom.
– It forms a tetrahedron shape and is held together by chemical bonds between O & Si
– It is the building block of the silicate minerals.
– Silicates = mineral compounds containing Silicon and Oxygen
• They may also contain one or more metallic elements (Al, Fe, etc.)
Quartz
Minerals are identified and classified by visual inspection, and
by performing simple tests to determine their physical properties
Minerals are most often identified by inspecting their Physical and
Chemical properties.
Color is the most easily observed, but least reliable property of a mineral for identification.
This is because the color of many minerals varies with the kind of impurities in the mineral.
Luster is the way in which a mineral shines in the light.
•Metallic luster – shine like polished metal. •Ex.) galena, pyrite
•Nonmetallic luster – not shiny.•Can be vitreous (shiny glass), Pearly, adamantine(hard brilliant luster like diamond), greasy, oily, dull, earthy.
•Ex.) Quartz = vitreous•Ex.) Mica = pearly
Types of Luster
Streak is the color of the powder left on a streak plate when a mineral is rubbed on it.
Streak is much more reliable than color because, although the color of a mineral changes, its streak does not.
GENERAL RULES TO FOLLOW WITH STREAK:•Metallic minerals are usually at least as dark as the specimen.•Nonmetallic minerals are usually colorless or white.
Cleavage is the tendency of a mineral to split in a particular direction.
•Helps with identifying the mineral because cleavage surfaces can be seen on tiny mineral grains.•Mineral splits along the weaker bonds
•Ex.) Mica, has 1 good cleavage(BASAL) (splits in 1 direction = into a sheet)•Feldspar, has 2 good cleavages (splits into 2 directions, at or near right angles)
Basal/ “Sheety” Cleavage
Feldspars always cleave readily at or near right angles.
Fracture is the tendency of a mineral to break in directions other than along crystal faces or cleavage surfaces.
•Ex.) Quartz and obsidian – both have Conchoidal or shell-like fracture
Conchoidal or shell-like fracture
Fibrous facture
Hardness is the resistance of a mineral to being scratched.
The Mohs Hardness Scale is one of the most effective tool for identifying minerals.
• Atoms can be arranged differently to produce different minerals.
• The arrangement of the minerals’ atoms, ions, or molecules determines the mineral’s hardness
– Ex.) Diamond (C) –vs- Graphite (C)
(the hardest mineral) (very soft mineral the flakes easily)
Atoms arranged in a tetrahedral
network
Atoms arranged in sheets of hexagonal networks
Specific Gravity
• The ratio of the mineral’s mass to the mass of an equal volume of water.
– Tells you how many times denser the mineral is than water.
– Calculate Density, divide mass over volume.
D=M/V•1st weigh mineral (mass)•2nd place in cylinder of water –figure out displacement (volume)•3rd find density (D=M/V)
Chemical Tests• Identified by the chemical bonds/makeup of
the minerals.– Ex.) Calcite (CaCO3), is the main mineral in limestone and
marble. When hydrochloric acid (HCl) is dropped on calcite it will fizz. The limestone fizzes because the carbon is reacting with the HCl and as a result bubbles are being released.
Only 30 of the 4,000 known minerals are common.
These 30 minerals are known as the rock-forming minerals
Most rock-forming minerals are…
•Silicates are composed of Silicon (Si) and Oxygen (O), and usually one or more metallic elements.•90% of mineral in Earth’s crust are silicates•The percent composition of Silicate minerals in a rock determines the type of rock it is.
•High Silica content forms light-colored rocks•While lower (but only by about 25%) Silica content forms darker-colored rocks
Rocks that have a high percentage of Silicates are light in color, and are
called Felsic rocks.
Rocks that have a low percentage of Silicates are dark in color, and are
called Mafic rocks.
Rocks are often made of several different minerals.
Examples of Silicate Minerals
• Quartz – (SiO2) consists of tightly bonded silica tetrahedra made of 2 O atoms for each Si atom.
– Luster = glassy or greasy
– Colorless or white if pure and has conchoidal or irregular fractures
– Hardness= 7
– Found in granite rock
– Most sands contain quartz
– Used in jewelry, prisms, heat lamps, glass, paint
Quartz
Pink Granite
Examples of Silicate Minerals
• Feldspars – make up 60% of the crust– Used in glass and ceramics
– Has 2 direction cleavage
– Hardness = 6
– Luster = pearly
– Usually made of Al and O plus a metal
– Classified into 2 major groups:• Potassium Feldspar
• Sodium-Calcium Feldspar
Examples of Silicate MineralsDifferent types of Feldspars
Potassium Feldspar / “Orthoclase”- light colored pink or salmon- 2 cleavages that meet at right angles- found in granite
Sodium-Calcium Feldspar / “Plagioclase” -- white to grey-2 cleavages that meet at slightly less than right angles- 1 cleavage often has fine parallel lines called striations.
“Orthoclase”Sodium-Calcium Feldspar
Examples of Silicate Minerals
• Pyroxenes – (ferromagnesian silicates = FeMg)
– Cleavages meet at nearly right angles
– Harness = 5 &6
• Ex. Augite (dark mineral , so has less silica)
Examples of Silicate Minerals• Micas – form flat crystals
– Hardness = 2.5
– Perfect cleavage that can be picked out of rocks (like granite or gneiss)• Cleave in 1 direction that form thin sheets
– Used in paints, plastics, rubber, roofing• Ex.) Muscovite – silvery white, Biotite- dark brown/black
Examples of Silicate Minerals
• Amphiboles – form long, needle-like crystals
– Hardness = 5-6
– Has 2 good cleavages that meet at oblique angles
– Found in igneous and metamorphic rocks
• Ex.) Hornblende – shiny, dark green brown or black.
Examples of Silicate Minerals
• Olivines – (ferromagnesian silicate)
– Olive green in color
– Hardness = 6.5
– Glassy, shell-like fracture
• Ex.) Peridotite – used in jewelry
Examples of Silicate Minerals• Kaolinites – (Aluminum silicate)
– Forms by weathering feldspars and other silicates
– White
– Hardness s= 2
– Perfect cleavage in 1 direction
– Used in china clay, ceramics, paints, fiberglass
Carbonate Mineral Groups
•Minerals made of negatively charged carbonate ions bonded to positive metal ions.•Consists of 1 C atom covalently bonded to 3 O atoms.
•Example of carbonate rocks are limestone and marble.
Examples of Carbonate Minerals
• Calcite – (calcium carbonate – CaCo3)– Most common carbonate mineral
– Colorless to white
– Hardness = 3, can be scratched with a knife
– Has 3 perfect cleavages that meet at oblique angles, so breaks into flat-sided rhombohedra
– Can use acid test to identify it (HCl)
Examples of Carbonate Minerals
• Dolomite – [calcium magnesium carbonate = CaMg(Co3)2]
– Cleaves into rhombohedra
– Occurs as coarse or fine grained
– Doesn’t always bubble with hydrochloric acid (HCl).
Oxides and Sulfide Mineral Groups
•Iron (Fe) containing minerals•Used in industry to make steel, magnets, car parts, etc. Also used in consumer goods as medicines, cosmetics, plastics, and paints
•Oxide = metal combined with Oxygen•Sulfide = metal combined with Sulfur.
• Hematite – most common iron oxide
– Color = red usually, and has an earthy luster and uneven fractures. Sometimes it is silvery metallic.
– Streak = red-brown streak on steak plate
– Hardness = 5-6
Examples of Sulfide Minerals
• Magnetite – black iron oxide
– Attracted to a magnet (so its magnetic).
– Hardness = 5.5-6.5
Ex.) Loadstone
Examples of Sulfide Minerals
• Pyrite – Iron sulfide, known as “fools gold”
– Color = pale brass to golden brown
– Hardness= 6
– Often has 6-12 sided crystals
Examples of Sulfide Minerals