OGT ReviewOGT Review

ElementsElements

Elements are the basic building Elements are the basic building blocks of matter.blocks of matter.

There are 115 known elements.There are 115 known elements. This number changes as new This number changes as new

elements are created in research elements are created in research labs.labs.

90 elements occur in nature and 90 elements occur in nature and fewer than half of them are common.fewer than half of them are common.

Elements ContinuedElements Continued

Elements are listed on the Periodic Elements are listed on the Periodic Table of Elements by atomic number Table of Elements by atomic number (number of protons).(number of protons).

Elements are composed of atoms.Elements are composed of atoms.

AtomsAtoms

Atoms are the smallest particle of an Atoms are the smallest particle of an element that has the properties of element that has the properties of that element.that element. John Dalton (1803)- Modern atomic John Dalton (1803)- Modern atomic

theory.theory.All atoms of a particular element All atoms of a particular element are alike, but they are different are alike, but they are different from the atoms of any other from the atoms of any other element.element.

Atoms ContinuedAtoms Continued

Atoms are made up of protons, Atoms are made up of protons, neutrons and electrons (subatomic neutrons and electrons (subatomic particles).particles). Protons have a positive charge (+)Protons have a positive charge (+) Electrons have a negative charge (-)Electrons have a negative charge (-) Neutrons have no chargeNeutrons have no charge

Atoms ContinuedAtoms Continued Protons and neutrons make up the nucleus of Protons and neutrons make up the nucleus of

an atom.an atom. Electrons orbit (circle) the nucleus.Electrons orbit (circle) the nucleus.

Move around the nucleus in shells or energy Move around the nucleus in shells or energy levels.levels.

The further away from the nucleus a shell is, The further away from the nucleus a shell is, the more electrons it can hold and therefore the more electrons it can hold and therefore it has a higher energy level.it has a higher energy level.

The inner most level can hold 2 electrons, The inner most level can hold 2 electrons, the second can hold 8, the third up to 18 the second can hold 8, the third up to 18 and so on.and so on.

The outer most shell (valence) can hold no The outer most shell (valence) can hold no more than 8 electrons.more than 8 electrons.

The Periodic TableThe Periodic Table

Elements are arranged by atomic number Elements are arranged by atomic number (number of protons in the nucleus).(number of protons in the nucleus).

Vertical columns are called groups or Vertical columns are called groups or families.families.

Horizontal rows are called periods.Horizontal rows are called periods. Elements located in the same group have Elements located in the same group have

similar electron configurations (same similar electron configurations (same number of valence electrons). Therefore number of valence electrons). Therefore they will react in similar ways.they will react in similar ways.

Changes in MatterChanges in Matter

Scientists know of millions of Scientists know of millions of different substances in the different substances in the world.world.How is this possible if there How is this possible if there

are only 115 known elements?are only 115 known elements?Elements combine to form Elements combine to form

different substances.different substances.

Chemical BondsChemical Bonds

Atoms are held together in Atoms are held together in molecules by chemical bonds.molecules by chemical bonds.

Chemical bonds store energy.Chemical bonds store energy.

Ionic BondsIonic Bonds Ions are formed when an atom gains or Ions are formed when an atom gains or

loses an electron to become + or -.loses an electron to become + or -. Sodium (Na) can lose its valence electron Sodium (Na) can lose its valence electron

to form a sodium ion (Nato form a sodium ion (Na++).). Chlorine (Cl) can gain an electron to form Chlorine (Cl) can gain an electron to form

a chlorine ion (Cla chlorine ion (Cl--).). An ionic bond is formed when two ions of An ionic bond is formed when two ions of

opposite charges (metal and nonmetal) opposite charges (metal and nonmetal) are attracted to each other and form a are attracted to each other and form a new substance.new substance.

NaCl: Sodium Chloride (table salt).NaCl: Sodium Chloride (table salt).

Covalent BondsCovalent Bonds

Covalent bonds are formed between atoms Covalent bonds are formed between atoms of two nonmetals.of two nonmetals.

Electrons are shared.Electrons are shared. Example: Carbon can share electrons Example: Carbon can share electrons

with 2 oxygen atoms (1 with each) to with 2 oxygen atoms (1 with each) to form carbon dioxide (COform carbon dioxide (CO22).).

Covalent bonds are stronger than ionic Covalent bonds are stronger than ionic bonds because of this sharing of bonds because of this sharing of electrons.electrons.

pHpH

The pH scale refers to strength of an The pH scale refers to strength of an acid or a base.acid or a base.

The scale ranges from 0-14.The scale ranges from 0-14. 0 is the most acidic. (hydrochloric 0 is the most acidic. (hydrochloric

acid)acid) 14 is the most basic. (sodium 14 is the most basic. (sodium

hydroxide)hydroxide) 7 is neutral. (water)7 is neutral. (water)

Chemical Equations Chemical Equations ContinuedContinued

Chemical equations must be Chemical equations must be balanced. This means that each balanced. This means that each element appears the same number element appears the same number of times in both the reactants and of times in both the reactants and products.products. Example:Example:

C + OC + O22 CO CO22

If there are different amounts of If there are different amounts of each element on either side of an each element on either side of an equation we must balance it using equation we must balance it using coefficients.coefficients. Example:Example:

HH22 + O + O2 2 H H22OO

This is not balanced. To balance we This is not balanced. To balance we add coefficients.add coefficients.

2 2 HH22 + O + O22 2 2 HH22OO

States of EnergyStates of Energy

Potential Energy (PE) – Stored Potential Energy (PE) – Stored energyenergy Gasoline (chemical)Gasoline (chemical) Rock on a cliff (position)Rock on a cliff (position) Food (chemical)Food (chemical) Coal (chemical)Coal (chemical)

Kinetic Energy (KE) – energy an Kinetic Energy (KE) – energy an object has when it is moving.object has when it is moving. Falling rockFalling rock Thrown ballThrown ball RunnerRunner WaterfallWaterfall

End of Physical End of Physical Science ReviewScience Review

ConductionConduction

Conduction is the transfer of heat by Conduction is the transfer of heat by direct molecular contact.direct molecular contact. Metals are good conductors of heat.Metals are good conductors of heat. Example: If you hold a metal rod in fire Example: If you hold a metal rod in fire

the heat will quickly distribute between the heat will quickly distribute between the molecules in the rod and it will the molecules in the rod and it will become hot.become hot.

ConvectionConvection

Convection is the transfer of heat by Convection is the transfer of heat by the flow of a liquid or a gas.the flow of a liquid or a gas. Warm air in a room rises and cool air Warm air in a room rises and cool air

sinks. This causes a circular motion sinks. This causes a circular motion called a convection current.called a convection current.

RadiationRadiation

Radiation is the transfer of heat Radiation is the transfer of heat through space in the form of waves.through space in the form of waves. Heat from the sun travels through the Heat from the sun travels through the

vacuum of space to reach Earth.vacuum of space to reach Earth.

Wave DiagramWave Diagram

What is Force?What is Force?

A A forceforce is a push or pull that is is a push or pull that is exerted on an object.exerted on an object. Force stops motionForce stops motion: gloved hand : gloved hand

catching a ballcatching a ball Force slows motionForce slows motion: friction slowing a : friction slowing a

skateboardskateboard Force changes directionForce changes direction: tennis racket : tennis racket

striking a tennis ballstriking a tennis ball

GravityGravity

Law of Universal GravitationLaw of Universal Gravitation states that in the universe every states that in the universe every mass attracts every other mass.mass attracts every other mass. Greater mass = greater gravitational Greater mass = greater gravitational

forceforce An apple falls to Earth because the An apple falls to Earth because the

Earth is much more massive.Earth is much more massive.

FrictionFriction

Friction is a force that resists motion.Friction is a force that resists motion. It must be overcome to start an object It must be overcome to start an object

moving and/or to keep it moving.moving and/or to keep it moving.

Rougher surface+Heavy object = More Rougher surface+Heavy object = More frictionfriction

Smooth surface+Light object = Less Smooth surface+Light object = Less frictionfriction

Speed and VelocitySpeed and Velocity

SpeedSpeed and and velocityvelocity are terms used are terms used to describe the motion of an object.to describe the motion of an object. Speed is the distance traveled over a Speed is the distance traveled over a

certain period of time.certain period of time. Velocity is the same but includes a Velocity is the same but includes a

specific direction (north, east, specific direction (north, east, southwest, etc.)southwest, etc.)

The equation used to determine both The equation used to determine both speed and velocity is distance divided by speed and velocity is distance divided by time.time.S = d/tS = d/t V = d/tV = d/tUnits for measuring speed/velocity:Units for measuring speed/velocity:

Kilometers/hour (km/hr)Kilometers/hour (km/hr)Miles/hour (mi/hr)Miles/hour (mi/hr)Feet/second (ft/s)Feet/second (ft/s)Meters/minute (m/min)Meters/minute (m/min)Centimeters/second (cm/s)Centimeters/second (cm/s)

AccelerationAcceleration

Acceleration is the rate in change in Acceleration is the rate in change in velocity.velocity. Can be used to describe increased or Can be used to describe increased or

decreased (deceleration) change.decreased (deceleration) change. Acceleration is calculated by Acceleration is calculated by

subtracting an object’s starting subtracting an object’s starting velocity from it’s final velocity and velocity from it’s final velocity and dividing by time.dividing by time.A = vA = vff – v – vss / t / t

Motion of falling objectsMotion of falling objects

Gravity causes objects released Gravity causes objects released above Earth’s surface to fall to the above Earth’s surface to fall to the ground.ground.

Mass, size and shape of the object Mass, size and shape of the object determines how fast it will fall.determines how fast it will fall.

Air resistance (air drag) also affects Air resistance (air drag) also affects falling objects.falling objects. In a vacuum (no air) all objects will fall In a vacuum (no air) all objects will fall

at the same rate because gravity is the at the same rate because gravity is the only force acting on them.only force acting on them.

SpheresSpheres

The Earth consists of 3 spheres:The Earth consists of 3 spheres:

1.1. The The lithospherelithosphere (rock sphere) (rock sphere)

2.2. The The hydrospherehydrosphere (water sphere) (water sphere)

3.3. The The atmosphereatmosphere (gas sphere) (gas sphere)

These are smaller parts of the These are smaller parts of the BiosphereBiosphere: The place where all : The place where all life exists on Earth.life exists on Earth.

Interaction of Air, Land, Interaction of Air, Land, and Waterand Water

Weathering is the breaking down of Weathering is the breaking down of rocks into smaller pieces.rocks into smaller pieces. Physical weathering: water seeps into Physical weathering: water seeps into

cracks in rock and freezes, the water cracks in rock and freezes, the water expands, breaking the rock apart.expands, breaking the rock apart.

Chemical weathering: oxygen and Chemical weathering: oxygen and water chemically react with iron water chemically react with iron mineral in rocks, turning to rust, which mineral in rocks, turning to rust, which crumbles away easily. crumbles away easily.

ErosionErosion

Erosion is the process by which rock Erosion is the process by which rock material at Earth’s surface is removed material at Earth’s surface is removed and carried away.and carried away. Erosion requires a moving force (like Erosion requires a moving force (like

water).water).Example: Streams and rivers turn a Example: Streams and rivers turn a muddy brown after a heavy rain due muddy brown after a heavy rain due to the rock material in the water.to the rock material in the water.

Glaciers and wind can also contribute Glaciers and wind can also contribute to erosion.to erosion.

Structure of the EarthStructure of the Earth

The Earth is composed of 3 layers.The Earth is composed of 3 layers. The crust: outermost layer (5-50 km)The crust: outermost layer (5-50 km) The mantle: middle layer (~2900 The mantle: middle layer (~2900

km)km) The core: innermost layer The core: innermost layer

Outer core (~2300 km)Outer core (~2300 km)Inner core (~1200 km): Inner core (~1200 km): Thought to be solidThought to be solid

Theory of Continental Theory of Continental DriftDrift

1912: Alfred Wegener proposed 1912: Alfred Wegener proposed the continents were drifting the continents were drifting across Earth’s surface.across Earth’s surface. Based on how the shapes of the Based on how the shapes of the

continents fit together like a continents fit together like a puzzle.puzzle.

The original “super continent” The original “super continent” was called Pangea.was called Pangea.

Plate TectonicsPlate Tectonics

Earth’s crust is broken into pieces, or Earth’s crust is broken into pieces, or plates, that slowly move and interact at plates, that slowly move and interact at their boundaries in various ways.their boundaries in various ways. Caused by heat circulating in the Caused by heat circulating in the

mantle.mantle. There are 10 major plates: The There are 10 major plates: The

Pacific, North American, Nazca, Cocos, Pacific, North American, Nazca, Cocos, South American, African, Arabian, South American, African, Arabian, Eurasian, Indian, and Antarctic.Eurasian, Indian, and Antarctic.

Plate InteractionsPlate Interactions As the plates move, some are colliding, As the plates move, some are colliding,

some are spreading apart, and some are some are spreading apart, and some are sliding past one another.sliding past one another. Subduction zone: When an oceanic Subduction zone: When an oceanic

plate collides with a continental plate it plate collides with a continental plate it tends to slide down under it. This tends to slide down under it. This forms mountains and volcanoes.forms mountains and volcanoes.

Fault zones: When one plate slides Fault zones: When one plate slides sideways past another. This sometimes sideways past another. This sometimes causes severe earthquakes.causes severe earthquakes.

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Earth’s Geologic HistoryEarth’s Geologic History

Scientists have pieced together Scientists have pieced together much of Earth’s history by studying much of Earth’s history by studying rocks.rocks.

There are 3 main rock types:There are 3 main rock types: SedimentarySedimentary IgneousIgneous MetamorphicMetamorphic

Sedimentary RockSedimentary Rock

Most commonly formed by the Most commonly formed by the deposition of particles underwater. deposition of particles underwater. (dirt being submerged)(dirt being submerged)

About 75% of land surface is About 75% of land surface is covered with sedimentary rocks.covered with sedimentary rocks.

Igneous RockIgneous Rock

Form from hot molten rock material, Form from hot molten rock material, either underground (magma) or on either underground (magma) or on Earth’s surface (lava)Earth’s surface (lava)

VolcanoesVolcanoes

Metamorphic RockMetamorphic Rock

Form from pre-existing rocks that Form from pre-existing rocks that undergo changes caused by extreme undergo changes caused by extreme heat and/or pressure.heat and/or pressure.

Plate motionsPlate motions

Distances in SpaceDistances in Space

Distances in space are so great they Distances in space are so great they are difficult to comprehend.are difficult to comprehend.

The distance between Earth and the The distance between Earth and the nearest star (besides the sun) is nearest star (besides the sun) is 41,000,000,000,000 km. (41 trillion)41,000,000,000,000 km. (41 trillion)

We use light-years to express We use light-years to express distances in space.distances in space.A light-year is the distance light A light-year is the distance light

travels in a year.travels in a year.

The Big Bang TheoryThe Big Bang Theory

According to this theory, all the According to this theory, all the matter and energy that exists in the matter and energy that exists in the universe today was once universe today was once concentrated in a very small, dense concentrated in a very small, dense object about the size of an atom.object about the size of an atom. For some unknown reason this object For some unknown reason this object

suddenly expanded creating the suddenly expanded creating the beginning of space and time.beginning of space and time.

Matter continued to move away and over Matter continued to move away and over time small amounts combined to form time small amounts combined to form stars and planets.stars and planets.

EvidenceEvidence

The universe is expanding outward The universe is expanding outward (Red Shift).(Red Shift).

Galaxies are slowly moving apart.Galaxies are slowly moving apart. Galaxies are determined to be about Galaxies are determined to be about

15 billion years old.15 billion years old. Large quantities of a hydrogen Large quantities of a hydrogen

isotope are scattered throughout the isotope are scattered throughout the universe (remnants of big bang).universe (remnants of big bang).

The Solar SystemThe Solar System

Scientists believe that our solar system Scientists believe that our solar system formed about 5 billion years ago.formed about 5 billion years ago. After the “Big Bang” some gases and After the “Big Bang” some gases and

dust became our star (sun).dust became our star (sun). The leftover material condensed into The leftover material condensed into

planets, satellites, comets, planets, satellites, comets, meteoroids and asteroids.meteoroids and asteroids.

The sun contains 99% of all matter in The sun contains 99% of all matter in our solar system.our solar system.

Types of SymbiosisTypes of Symbiosis

Mutualism: When both organisms Mutualism: When both organisms benefit. (butterfly/flower)benefit. (butterfly/flower)

Commensalism: When one organism Commensalism: When one organism benefits and the other is not benefits and the other is not affected. (remora/shark)affected. (remora/shark)

Parasitism: When one organism Parasitism: When one organism benefits and the other is harmed. benefits and the other is harmed. (tapeworm/animal)(tapeworm/animal)

MutualismMutualism

CommensalismCommensalism

ParasitismParasitism

OverpopulationOverpopulation

Overpopulation, competition, and Overpopulation, competition, and changes in the environment challenge changes in the environment challenge the survival of all individuals within a the survival of all individuals within a population (same species).population (same species). More individuals than the More individuals than the

environment can support.environment can support. Competition for resources: food, Competition for resources: food,

territory, shelter and mates.territory, shelter and mates. Most do not survive to reproduce.Most do not survive to reproduce.

VariationsVariations Due to variations (differences) Due to variations (differences)

among members of a species, some among members of a species, some individuals are better adapted.individuals are better adapted.

These organisms survive to These organisms survive to reproduce while others die out.reproduce while others die out.Natural SelectionNatural Selection: “Survival of : “Survival of

the Fittest”, “Only the Strong the Fittest”, “Only the Strong Survive” etc. – Darwin’s TheorySurvive” etc. – Darwin’s Theory

NATURAL SELECTION

A major misconception about natural selection!

http://evolution.berkeley.edu/evosite/misconceps/IEneeds.shtml

Evolution – the basicsEvolution – the basics

1. over population1. over population 2. constant struggle for 2. constant struggle for

resourcesresources 3. variation in the species3. variation in the species 4. the best adapted to the 4. the best adapted to the

environment surviveenvironment survive 5. surviving organisms transmit 5. surviving organisms transmit

variation to offspringvariation to offspring

Random factsRandom facts

ATP – cellular energyATP – cellular energy COCO22 taken in and O taken in and O22 given off – given off –

photosynthesisphotosynthesis Flagella – moves a cellFlagella – moves a cell Mitochondria – makes cellular Mitochondria – makes cellular

energyenergy Placebo – fake drugPlacebo – fake drug EthicsEthics