Post on 29-Jan-2016
Chapter 9: Rocks and Minerals
October 29 – December 11
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Scientist of the Day
Frederick Soddy• Worked with Rutherford• Discovered different types of
radiation• Nobel Prize in chemistry• Started writing books about
economics insteado People thought he was a crackpot,
but his ideas are used todayo Predicted that economy would run
on fossil fuels instead of gold
• Was going to have an element named after him, but “Soddyium” sounds like sodium
Scientist of the Day
Rita Levi-Montalcini• Wanted to be a writer; twin
sister a painter• Friend died of cancer –
decided to be a doctor instead• Lost job in WWII Italy because
she was Jewish• Started working in her
bedroom, then as a refugee• Discovered how nerves grow• Won 1986 Nobel Prize in
medicine
Scientist of the Day
Ada Lovelace• Lord Byron’s daughter• Mother didn’t want her to
be a poet, so she only learned math & logic
• Socialite• Met Charles Babbage
(inventor of computer) at a party
• Wrote the first computer program/algorithm
• Famous science writer too
Scientist of the Day
Clair Patterson• Worked on Manhattan
Project• New techniques for figuring
out the age of artifacts, meteorites, the earth, etc (kind of like carbon dating)
• Age of the earth = 4.5 billion years
• Kept finding lead in everything
• Traced it back to leaded gasoline – it was poisoning people!
Minerals and Molecules
November 9, 20157th grade Chapter 9.1
Atoms• Atom: Smallest unit of matter.
o Except not really, because atoms are made up of ‘subatomic particles’
• Substances made of one type of atom are called elements.
• There are only 118 known elements in the universeo You can see them all on the periodic table (which is a
little out of date)o Each atom has a symbol. E.g. Oxygen is O.
• All of them (except hydrogen and helium) were made in stars
Molecules• Molecule: 2 or more atoms stuck together to
make a substance (chemical). The atoms are joined with chemical bonds
• Chemical bond: force of attraction between 2 atoms
Symbols for Molecules
HBrO4
Each atom has a symbolfrom the periodic table Symbols can be 1 or 2 letters.
First = capital, second = lower case or none
Numbers say how manyNo number = 1
Practice!• How many/what type of atoms do these
molecules have?
• H2O
• CuBr2
• HgCl2• NaCl• KNO3
What do molecules and minerals have in
common?• They are both types of matter, so they are
made of atoms• Minerals and molecules are both substances
o This means they have specific properties that are always the same
• Can sometimes be grown in crystal shapes• Both have chemical formulas (symbols for
writing the name)• Small changes in what they’re made of can be
big changes in their chemical and physical properties
SiO2• SiO2 is a very common substance – sand, glass,
quartz, amethyst• SiO2 can be different minerals
o Dope with small amounts of other elementso Change crystal shape when it’s forming
Properties of Minerals
November 11, 20157th grade Chapter 9.1
Symbols for Molecules
HBrO4
Each atom has a symbolfrom the periodic table Symbols can be 1 or 2 letters.
First = capital, second = lower case or none
Numbers say how manyNo number = 1
Mineral Molecules
CaSO4· 2H2O
This dot shows up in a lot of minerals’ chemical formulas.
It means that for every CaSO4 molecule, there are
2 H2O molecules in the same place. Together, they make gypsum
MineralsMineral: naturally occurring solid that can be formed by inorganic processes, has a crystal structure, and a defined chemical composition
• Defined chemical composition means that it’s a single type of molecule, so you can also call a mineral a substance
• 5 traits to define a mineral
Dioptase (CuSiO3·H2O)
5 Traits of Minerals1. Naturally occurring
o You can make things that look like minerals in a lab, but they’re not “official” minerals unless they’re also found in nature.
2. Solid3. Crystal Structure
o Flat sides, sharp edges (based around prism shapes from math class!)
4. Forms by inorganic processeso You can sometimes form minerals in the body (e.g. kidney
stone), but it’s not an “official” mineral unless you can also make it with things that aren’t plants or animals
5. Definite chemical compositiono You can write a chemical formula for them
Identifying MineralsMinerals are identified mainly by their physical properties
1. Color2. Streak3. Luster4. Hardness5. Density6. Crystal structure7. Cleavage8. Fracture
Marcasite (FeS2)
StreakStreak: color of a mineral’s powder.
• Sometimes different shapes of the same mineral look like different colors, but when you grind them up, it will be the same color
• This used to be very important for making paint!
Lazurite ((Na,Ca)8[(S,Cl,SO4,OH)2 · (Al6Si6O24)])
LusterLuster: how shiny a mineral is/how light is reflected from it
• Uses words like metallic, glassy, earthy, silky, waxy, greasy, pearly
Fluorite (CaF2)
HardnessHardness: how easy it is to scratch a mineral or scratch something else with it
• Measured with Mohs hardness scale• 1= soft, 10=hard
Azurite (Cu3(CO3)2(OH)2)
Cleavage & FractureCleavage: splits easily along flat surfaces
Fracture: what it looks like when it splits
Pyrope (Mg3Al2Si3O12)
Forming Rocks & Minerals
December 1, 20157th grade Chapter 9.1, part 2
MineralsMineral: naturally occurring solid that can be formed by inorganic processes, has a crystal structure, and a defined chemical composition
• Defined chemical composition means that it’s a single type of molecule, so you can also call a mineral a substance
• 5 traits to define a mineral
Dioptase (CuSiO3·H2O)
5 Traits of Minerals1. Naturally occurring
o You can make things that look like minerals in a lab, but they’re not “official” minerals unless they’re also found in nature.
2. Solid3. Crystal Structure
o Flat sides, sharp edges (based around prism shapes from math class!)
4. Forms by inorganic processeso You can sometimes form minerals in the body (e.g. kidney
stone), but it’s not an “official” mineral unless you can also make it with things that aren’t plants or animals
5. Definite chemical compositiono You can write a chemical formula for them
3 Ways to Form Minerals
Crystallization: the process of arranging atoms/molecules so that the substance has a definite crystal structure
1. From solutions2. From cooling lava3. From organic processes
o To be considered a mineral, the same thing has to also form at other times by inorganic processes
o E.g. Calcite can be made by clams and coral for their exoskeleton or in caves as stalactites (and other ways)
Solutions• Not the same thing as fixing a problem!
Solution: similar to a homogeneous mixture, but one substance is dissolved in another substance
• We’re usually talking about things dissolved in water, but it can be anything – technically doesn’t have to even be a liquid
• When substances leave a solution, crystallization occurs
What makes something leave a
solution?• Evaporation
o If you slowly remove the water, it leaves behind the other substance. Bigger crystals instead of sandy particles if it’s slow and not shaken
• Coolingo Usually, hot water can dissolve more of a substance in
the first place. If it gets cold, the substance no longer “fits”
• Chemical changeo If you dissolve one substance and it slowly changes into
something else, the new substance might not have the same solubility (a physical property)
Magma & Lava• Magma is molten rock beneath the earth’s crust• Lava is when it makes it to the surface• Magma & lava contain a lot of oxygen (O) and
silicon (Si), so they form a lot of silicateso Silicates make up most of the earth’s crust
• Type of mineral formed depends on speed, heat, pressure, elements present, etc
• Magma cools slowly• Lava cools quickly, so it makes smaller crystals
Silicates• Depending on how it
cools & what else is present, silicates can form a bunch of different minerals because there are a bunch of different crystal structures possible
Where to find minerals• Depending on how they’re made, some minerals
are more common in certain areas
• If you are in an area with a lot of earthquakes, would you expect more or less minerals to be made from lava?
• If hot water with dissolved substances was pushed through a crack in a rock, what might form?
Classifying RocksDecember 2, 2015
7th grade Chapter 9.2
3 Ways to Form Minerals
Crystallization: the process of arranging atoms/molecules so that the substance has a definite crystal structure
1. From solutions2. From cooling lava3. From organic processes
o To be considered a mineral, the same thing has to also form at other times by inorganic processes
o E.g. Calcite can be made by clams and coral for their exoskeleton or in caves as stalactites (and other ways)
Rocks vs Minerals• Rocks are usually mixtures of minerals and other
componentso Can be 1 mineral or several
• 4 main traits to classify rocks:
1. Mineral composition2. Color3. Texture4. Origin
TextureTexture: the look and feel of a rock’s surface.
• Texture comes from grains• Described by size, shape, and pattern of grains
Grain: particle of mineral or other rock inside a rock.
• Size can be small (fine) or coarse (large)• Shape can be rounded or jagged• Pattern can be nonbanded or banded (flat lines,
swirls, etc)
Rock Origins• 3 major groups for rocks• Determine rock group based on other properties
Igneous rock: formed from cooling magma or lava
Sedimentary rock: forms when particles of other rocks, plants, or animal remains are pressed and cemented together
Metamorphic rock: when a rock is changed by heat, pressure, or chemical change, usually deep underground
Silicates• Depending on how it
cools & what else is present, silicates can form a bunch of different minerals because there are a bunch of different crystal structures possible
Where to find minerals• Depending on how they’re made, some minerals
are more common in certain areas
• If you are in an area with a lot of earthquakes, would you expect more or less minerals to be made from lava?
• If hot water with dissolved substances was pushed through a crack in a rock, what might form?
3 Types of RocksDecember 9, 2015
7th grade Chapter 9.3-9.5
Rocks vs Minerals• Rocks are usually mixtures of minerals and other
componentso Can be 1 mineral or several
• 4 main traits to classify rocks:
1. Mineral composition2. Color3. Texture4. Origin
Rock Origins• 3 major groups for rocks• Determine rock group based on other properties
Igneous rock: formed from cooling magma or lava
Sedimentary rock: forms when particles of other rocks, plants, or animal remains are pressed and cemented together
Metamorphic rock: when a rock is changed by heat, pressure, or chemical change, usually deep underground
Igneous Rocks• Formed from magma or lava, which is high in
silica• When it forms below the crust, it’s called
intrusive• Above the crust, extrusive
Trends (Not Always True):• High in silica = dark rocks• Low in silica = lighter-colored rocks• When it cools quickly, it’s hard to form big
crystals, so very fine grains in the texture.• Hard, dense, and durable = good for arrowheads,
countertops, fortresses
Sedimentary RocksSediment: small, solid particles of rocks or living things
• Sedimentary rocks form when sediment is deposited by water or wind and eventually stuck together
• Usually soft• Sandstone and limestone are important building
materials – sometimes used to make concrete too
Forming Sedimentary Rocks
Weathering & Erosion Deposition Compactio
nCementati
on
3 Types of Sedimentary Rocks
Clastic rock: rock fragments are squeezed together. Classified according to how big the particles are. E.g. conglomerate, shale, sandstone
Organic rock: formed when remains of plants or animals are pressed together. E.g. coal from swamp plants, limestone from shells & skeletons that are high in calcium
Chemical rock: usually formed from solutions. E.g. Rock salt, limestone when it’s from evaporation
Metamorphic Rocks• Start off as sedimentary or igneous rocks, then
are changed by heat, pressure, chemical changes, or a combo of these processes. E.g. marble, slate
• Appearance, texture, and crystal structure of the minerals changes
• Classified by pattern of the grains• Used as building materials, old blackboard, etc.• Most metamorphic rocks are foliated
Foliated: thin, flat layers in a rock
End of Real Notes
Study chemical vs physical changes, rock cycle, and chapter 1-2 also!
Frankenlecture
October 28, 2015
What do these have in common?
• Ada Lovelace• Chemistry• Pee• Frankenstein• Frog legs• Ozymandias• Lord Byron• Batteries• Mary Shelley
The Book• Dr. Frankenstein uses modern
(for the time) science to turn dead parts into a living bodyo Electricity as the élan vital
• His monster is scary• It ends badly
• Extra scary at the time because this might be real scienceo 30 years before, Luigi Galvani
made dead frogs move with electricity
Élan Vital/Vis Vitalis• The spark of life! (Vital force)
At the time (not now):• People thought organic chemistry was totally
different from inorganic chemistry• Organic things like animals, fur, pee, dirt were
different from rocks, metals, etc• Organic things had (or had touched) the spark of
life – the élan vital!• Inorganic could never become organic• Galvani and Volta’s new batteries seemed to
change thato Frankenstein seems like logical progression
Friedrich Wöhler• His experiments failed,
but he found something better
• Was trying to help support Berzelius’ theory, ended up refuting it
• Made urea (pee), which was impossible
• Organic compounds from inorganic stuff
• Changed science!
Science FairDecember 7, 2015
Mandatory for 7th grade
What’s reasonable for science fair?
7th grade HAS to do this. 6th & 8th optional.
• Testing an idea by experiment!• You do it yourself (don’t just do what your parents
tell you or let them take over)• It doesn’t cost too much money – aim for $20 or
less• If you have a really good idea and plans about
how to make it work, Ms. B can help you get lab access at Notre Dame – no guarantees
Are your parents taking over?
• Is it your idea or theirs?• Do you need to use power tools? You should be
the one operating the tools or giving instructions to the Home Depot employee.
• Do you need a lab to complete the project? You should learn how to use/interpret the equipment (supervision expected).
Example• Probably not allowed to use a $500,000 machine,
but a grad student could run your sample and you could figure out how to read it:
Choosing a Project• Make sure it’s an experiment (that answers a question),
not just a demo (that only shows something cool)
Examples of Demos:• Baking soda & vinegar volcano• Marshmallow catapult• Building something from a kit• Rube Goldberg machineExamples of Experiments:• What is the best ratio of baking soda & vinegar to
produce CO2 quickly? What other variables will change the results?
• Does the catapult appear to obey the law of gravity exactly? What other factors are affecting the flight path?
Documentation• The difference between science and randomness
is writing it down.
• Write or type neatly!• All numbers should be written in metric/SI units.• Get a separate notebook or folder for science fair.• Be as objective as possible. (8th grade: use
empirical evidence)• Pictures are good!• When in doubt, write it down!
Lab Report1. Descriptive title – if someone only read this,
would they know what you’re doing?2. Question3. Hypothesis4. Materials list in metric units5. Procedure – how to do your experiment6. Results (Observations)7. Conclusions – what your results mean8. Reflection – sources of error, what to do next, etc
IdeasAdditional information about regionals: • http://sciencefair.nd.edu/
Project ideas: • http://www.education.com/science-fair/middle-sch
ool/• http://www.sciencebuddies.org/science-fair-projec
ts/science_project_ideas.php
• (Note that some of these ideas are better classified as demonstrations – feel free to modify them!)
Getting StartedDue Wednesday, even if you aren’t doing science fair:
• Write down your question, hypothesis, and a rough idea of how you’ll test it
• Ms. B will approve your idea, help you modify it, or ask for another idea
• Backup idea recommended!