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C165 Intro to Physical Sciences
Key Terms: ● Physics - study of forces, energy, and motion ● Chemistry - Study of atoms and molecules ● Earth Science - Focuses on earth’s structure and composition, as well as the processes that change earth ● Chemistry - the study of properties and interactions of substances ● Atoms - make up all living and nonliving things ● Molecules - made up of small atom particles that bond together ● Variables: the changing quantities in an experiment ● Physical Model - a good model explains current observations and predicts new ones ● Conceptual Models - used to visualize things that cannot be seen , such as atoms ● Mathematical Model - treat physical objects or phenomena using mathematical methods ● Principle of falsification - only falsifiable statements can be subject to scientific inquiry ● Hypothesis - a testable statement about how something in nature works ● Law - a concise statement that is supported by scientific evidence and repeated experiments and describes a widespread pattern in nature ● Theory - a statement that explains a wide range of observations and that is supported by a large body of scientific evidence ● Big bang theory - describes how the universe developed ● Field Study - observational studies done outside a laboratory setting ● Density - depends on the material itself, not on the object’s size or mass ● Speed - the distance traveled per interval ● Volume - the amount of space an object occupies ● Direct relationship - exists when an increase of one variable results in an increase in the other/a decrease in one variable results in a decrease in the other ● Inverse Relationship - when one increased the other decreases/one decreased the other increases ● Speed - how fast an object is moving ● Velocity - speed and direction ● Acceleration - a change in an objects velocity ● Force - a push or a pull on an object ● Balanced Forces - forces that combine to produce a net force of zero ● Newton’s First Law - the net force on an object is the cause of its acceleration
● Inertia - The tendency to keep the same motion ● Newton’s Third Law - whenever one object exerts a force on a second object, the second object exerts a force of the same magnitude in the opposite direction on the first object ● Friction - the force that opposes the motion of an object on which it acts ● Gravity - an attractive force that pulls objects closer together ● Static (Stationary) Friction - occurs between two objects that are touching each other but not moving against each other ● Kinetic (Moving) Friction - the force of friction between two objects that are moving against each other ● Linear Momentum - the mass of an object times its velocity ● Elasticity - the amount of bounce that an object has after a collision ● Work - the displacement of an object in the direction of an applied force ● Energy - the capacity to do work or to cause change ● Kinetic Energy - energy objects have because they are moving ● Potential Energy - energy that is stored ● Gravitational Potential Energy - energy that an object has due to its height above the ground ● Chemical Potential Energy - energy that is stored in the chemical bonds in a substance ● Elastic Potential Energy - energy that is stored in stretched springs, rubber bands, and similar objects ● Electrical Energy - energy that is carried by moving charged particles, such as electrons. ● Electromagnetic Energy (light energy) - energy that is carried by electromagnetic waves ● Thermal Energy - produced by the motions of atoms and molecules ● Law of Conservation of Energy - energy cannot be created or destroyed; it can only be transferred or converted from one form to another ● Oscillation - a repetitive motion that usually occurs about a center point or equilibrium ● Equilibrium - a position or state to which an oscillating object eventually returns after a disturbance is gone ● Mechanical Waves - can only travel through matter and require a medium to transport their energy ● Crest - the highest point reached by a particle ● Trough - the lowest point reached by a particle ● Amplitude (Transverse) - the vertical distance from the equilibrium to the crest or trough ● Amplitude (Longitudinal) - the measure of how compressed or expanded the medium becomes
● Chemical Change - a change in chemical composition ● Chemical Reaction - chemical bonds are formed or broken ● Microscopic Properties - have to do with the behavior of the individual atoms and molecules that make up the solid, liquid, or gas ● Macroscopic Properties - properties that can be observed when a large number of particles interact ● Ionic Bond - when a strong, attractive force occurs between the two ions because one is positively charged and the other is negatively charged, and the unlike charges are attracted to one another ● Covalent Bond - when two nonmetals react, neither one fully transfers electrons to the other; instead, the sharing of electrons provides the attractive force that holds the atoms together ● Metallic Bond - when metal atoms are bonded, the valence electrons move about freely from one metal atom to another ● Period - a row ● Group - a column ● Family - elements within a group that have the same number of valence electrons ● Metals - atoms that tend to lose electrons ● Nonmetals - have electrons that are very tightly associated with the nucleus ● Metalloids - Are shiny like metals but have an intermediate electrical conductivity, and are called semiconductors ● Nuclear Fusion - when hydrogen and other small nuclei fuse together to form larger nuclei, releasing large amounts of energy in the process ● Star - a celestial body that is held together by its own gravity and that releases visible light and other forms of radiant energy generated by nuclear fusion ● Galaxy - a collection of hundreds of billions of stars that are clustered together by gravity ● Orbit - when gravity causes one celestial body to move around another in a nearly circular path ● Meteoroid -smaller fragments of asteroids and other matter ● Comet - small, icy, dusty bodies that travel around the sun in very elliptical orbits ● Outer Planets - very large and are made primarily of gases such as nitrogen, hydrogen, and methane ● Solar System - the collection of objects that orbit a star ● Planet - a large, spherical object that orbits a star ● Asteroids - small rocky bodies that orbit the sun ● Planets orbit counterclockwise ● Inner Planets - are small, dense, and rocky ● Outer Planets - very large and are made primarily of gases such as nitrogen,
hydrogen, and methane ● Meteoroid -smaller fragments of asteroids and other matter ● Comet - small, icy, dusty bodies that travel around the sun in very elliptical orbits ● Axis of Rotation - the imaginary line from the north pole to the south pole on which a planet rotates ● Crust - the outermost rocky shell at the surface of earth that makes up the ground beneath your feet and the ocean floor ● Mantle - the thickest layer of the earth and makes up 84% of earth’s volume ● Core - made of primarily metal ● Weathering - the alteration or breakdown of rock or soil ● Physical Weathering - the result of mechanical processes (Temperature or pressure) ● Chemical Weathering - occurs when a rock’s composition changes (breakdown by chemical processes or reactions) ● Erosion - the mechanism responsible for the transportation or removal of material ● Deposition - the process in which soil, sediment, or rocks are added to a landform ● Sand Dunes - an example of the aeolian process requiring the same three basic elements for formation: a large quantity of loose and unvegetated sand, wind, and an obstacle ● Meanders - curves in a river ● River Valleys - Valleys that form when a river cuts down into the underlying bedrock ● Till - a mix of clay, sand, gravel, and boulders caused by glacial deposits ● Mineral - a naturally occurring, solid, inorganic element or compound that is formed by natural processes, has a limited range of possible chemical composition, and has a definite arrangement of atoms ● Sedimentary Rock - made up of weathered particles, such as sand, silt, clay, gravel, cobbles, or even occasionally boulders, that have been cemented together into hard rock ● Igneous Rock - formed by lava or magma ● Metamorphic Rock - has been changed from its original form ● Geologic Time Scale - a history of earth representing the different time periods of its geological evolution ● Analog - a close approximation, or direct analogy, of the long-term behavior of materials and processes found in a geologic feature ● Delta - formed at the mouth of a river when sediment deposits as the river current dissipates into a large non flowing body of water ● Principle of Superposition - in any sequence of undeformed sedimentary rocks,
○ All other conditions are kept the exact same ● The changing quantities are called variables ● The independent variable is the one that is being changed by the experimenter ● The dependent variable is the one that changes because of the independent variable ● The variables that scientists do not wish to study need to either be eliminated or kept constant ○ They are called control variables ● Observational studies are done with an individual’s own senses ○ Systems are observed as they appear in nature ● Computer Models - explain and predict natural phenomena, such as weather patterns and the detailed movements of objects in the solar system Lesson 5 ● In laboratory studies, researchers study the system of interest in a highly controlled, artificial setting ● Field Study - observational studies done outside a laboratory setting ○ Without changing or manipulating the system Lesson 6 ● A good model explains current observations and predicts new ones ● Conceptual Models can be used to visualize things that cannot be seen, such as atoms ○ Main goal is to capture the essential features of the system that it represents and to be easily understood by those who use the model ● Mathematical models treat physical objects or phenomena using mathematical methods ○ Formulas, graphs, or other mathematical means ● Computer Models - good in explaining and predicting natural phenomena such as weather patterns and the detailed movements of objects in the solar system Lesson 7 ● Principle of falsification - only falsifiable statements can be subject to scientific inquiry Lesson 8 ● Hypothesis - a testable statement about how something in nature works ○ Intended to be tested ● Law - a concise statement that is supported by scientific evidence and repeated experiments and describes a widespread pattern in nature ○ Intended to be universal
● Theory - a statement that explains a wide range of observations and that is supported by a large body of scientific evidence ○ A well-developed explanation that has been thoroughly tested Lesson 9 ● Theories are built on laws Lesson 10 ● The process of developing and modifying hypotheses, models, laws, and theories to account for the broadest possible range of observations is how science changes and how scientific knowledge has expanded Lesson 11 ● Big bang theory - describes how the universe developed ○ Universe expanded from a single point ● Steady-state theory - the universe was expanding but not changing its appearance over time Lesson 12 ● The theory of plate tectonics states that earth’s outermost layer, the lithosphere, is broken into many large pieces called tectonic plates ● The theory of plate tectonics explains these features: mid-ocean ridges are divergent boundaries, or places where two plates are moving apart, and deep ocean trenches occur at convergent boundaries, where plates collide Lesson 13 ● Law of conservation of mass - states that matter cannot be created or destroyed ● Law of definite proportions - states that a specific chemical substance always has the same ratio of elements by mass ● Law of multiple proportions - applies to the ratios of masses of elements involved when the same elements combine to form more than one substance ● Salton proposed that matter is composed of atoms and that elements are composed of only one kind of atom
Units and Measures
Lesson 14: The Metric System ● Systeme International d’Unites (SI) = worldwide ○ Length - Meters (m) ○ Mass - Kilogram (kg) ○ Time - Second (s)
○ Electronic balance - typically more precise ● Temperature = thermometer ● Volume = beaker or graduated cylinder ○ Graduated cylinder is more precise ● Liquid Displacement - the method of determining volume ○ Measure the volume of the liquid before and after you place the object in it Lesson 18: Direct and Inverse Relationships ● Direct relationship - exists when an increase of one variable results in an increase in the other/a decrease in one variable results in a decrease in the other ● Inverse Relationship - when one increased the other decreases/one decreased the other increases
Physics:
Force and Motion
Lesson 1: Speed and Velocity ● Speed - how fast an object is moving ● m/s = meters per second ● km/s = kilometers per second ● You can figure out an objects speed by dividing distance by the amount of time it took to travel ● Velocity - speed and direction Lesson 2: Acceleration ● Acceleration - a change in an objects velocity ● When acceleration is in the same direction as velocity, speed increases ● When acceleration is in the opposite direction from velocity, speed decreases Lesson 3: Force ● Force - a push or a pull on an object ● The SI unit for foce is the newton (N) Lesson 4: Direction and Magnitude of Net Force ● Net force is the combination of all the forces acting on an object ● Balanced Forces - forces that combine to produce a net force of zero Lesson 5: Newton’s First Law of Motion ● Newton’s First Law - the net force on an object is the cause of its acceleration
● Inertia - The tendency to keep the same motion ○ You can use inertia as a way to measure mass Lesson 6: Newton’s second law of motion ● The acceleration produced by the net force on an object is proportional to the net force and inversely proportional to the mass ● Acceleration = net force/mass Lesson 7: Newton’s Third Law of Motion ● Newton’s Third Law - whenever one object exerts a force on a second object, the second object exerts a force of the same magnitude in the opposite direction on the first object Lesson 8: Friction ● Friction - the force that opposes the motion of an object on which it acts Lesson 9: Kinetic and Static Friction ● Kinetic (Moving) Friction - the force of friction between two objects that are moving against each other ● Static (Stationary) Friction - occurs between two objects that are touching each other but not moving against each other Lesson 10: Applied Forces Lesson 11: Gravity ● Gravity - an attractive force that pulls objects closer together ● The greater the mass the greater the force of gravity it exerts ● Gravity exists between any two objects in the universe Lesson 12: Gravity and Friction ● Because friction only exists when objects are in contact with each other, it is known as a contact force ● Fluid Resistance - a special kind of friction that exists when an object moves through a gas or liquid Lesson 13: How Gravity Depends on Distance ● Gravity is inversely proportional to distance ○ Gravitational force decreases as objects get further away ● The law of universal gravitation states that gravity is inversely proportional to the square of the distance between the two objects ● Changes in distance have a greater effect on gravitational force than changes in
Lesson 21: The Law of Conservation of Energy ● Law of Conservation of Energy - energy cannot be created or destroyed; it can only be transferred or converted from one form to another Lesson 22: Applying the Law of Conservation of Energy Lesson 23: Wave Types ● Oscillation - a repetitive motion that usually occurs about a center point or equilibrium ● Equilibrium - a position or state to which an oscillating object eventually returns after a disturbance is gone ● Mechanical Waves - can only travel through matter and require a medium to transport their energy ○ Ocean waves and sound waves ○ Combination of an oscillating electric field and an oscillating magnetic field ● Electric fields occur when objects acquire an electrical charge ● Magnetic fields occur when an object has magnetic properties Lesson 24: Longitudinal and Transversal Waves ● Transverse wave - the oscillation is perpendicular to the direction the wave is traveling ○ Move up and down (like the ocean) ● Longitudinal Wave - the oscillation is parallel to the direction the wave is traveling ○ Compression and expansion (sound waves) ● Mechanical = transverse or longitudinal ● Electromagnetic = transverse only ● A wave transports its motion and energy from one place to another without transporting matter Lesson 25: Wavelengths, Frequency, Speed, and Amplitude ● Transverse Waves ○ Crest - the highest point reached by a particle ○ Trough - the lowest point reached by a particle ○ Amplitude - the vertical distance from the equilibrium to the crest or trough ■ Measured in meters ● Longitudinal Waves ○ Amplitude - the measure of how compressed or expanded the medium
becomes ● Wavelength - the horizontal distance after which the wave repeats itself in space ○ Distance between waves ● Period - the time needed for one oscillation ○ Crest to the trough back to the crest (time for one wave to pass) ○ Period = 1/frequency ● Frequency - tells you the number of oscillations the wave makes in a given amount of time ● The SI unit for frequency is one oscillation per second (Hertz)(HZ) Lesson 26: Explaining Electromagnetic Waves ● A combination of propagating electric and magnetic fields is called an electromagnetic wave (EM wave) ● Electromagnetic waves form when charged particles vibrate ● When a charged particle vibrates, it produces an oscillating electric field ○ This field produces an oscillating magnetic field ○ The combination of the elctric and magnetic fields forms the electromagnetic wave ● Electromagnetic waves can propagate even when there is no matter to carry them ● Electromagnetic waves in the same medium all travel at the same speed, the speed of light, which is about 3x10 to the 8th meters per second ○ Scientists use the symbol c to represent the speed of light in a vacuum ● The higher the frequency of an EM wave, the more energy it has ● Electromagnetic (EM) Spectrum describes the whole range of possible wavelengths or frequencies of electromagnetic radiation ○ Different parts of the spectrum have different wavelengths and frequencies ○ Wavelength decreases across the spectrum while energy and frequency increase
● Radio waves ○ Useful in learning about the structure of the universe ○ Communication ● Microwaves ○ Communication ○ Radar systems ○ Speed detecting radars ● Infrared Radiation ○ Skin senses it as heat ○ Devices that can detect infrared radiation can help you detect heat sources, see objects in the dark, detect blood flow in the body, and measure the temerature of objects from a distance ● Visible Light ○ Emitted by any object hot enough to glow ○ Lasers ■ Laser printers, CD and DVD players, weapon aiming systems, scientific research ● UV Radiation ○ Penetrate and damage cells ○ Damage viruses ○ Used to sterilize and sanitize air, water, surgical instruments, and even food ○ Used to detect counterfeit money and ID’s ○ Vitamin D ○ Skin Cancer ● X-Rays ○ Inside of the body ○ Scan luggage and packages ○ Used to study certain kinds of astronomical objects ■ Neutron stars ■ Black holes ● Gamma Rays ○ Easily penetrate most objects ○ Treat cancer ○ Produce images of the interior of an object Lesson 29: Sound Waves ● Compression - when particles of matter are pushed closer together ● Expansion - when particles of matter are pulled away from each other ● Pitch - how high or low a sound is ○ The higher the frequency the higher the pitch
● Loudness - the energy of a sound wave; the greater the energy of the wave, the greater its amplitude and, therefore, the louder the sound Lesson 30: Comparing Sound and EM Waves ● Sound Waves (mechanical) ○ Longitudinal ○ Cannot travel in a vacuum ○ Speed in air is about 330 meters per second ○ Speed in water is about 1500 meters per second ● Electromagnetic Wave ○ Transverse ○ Can travel through a vacuum at about 300 million meters per second ○ Speed in air is about 300 million meters per second ○ Speed in water is about 220 million meters per second
Chemistry
Lesson 1: Atoms: The Basic Unit of Matter ● Matter - anything that takes up space and has mass ● Atom - the basic building block of matter ● Proton - positive ● Electron - negative ● Neutron - neutral Lesson 2: Subatomic Particles ● The atomic structure is the arrangement of subatomic particles within the atom ○ Protons and neutrons are in the nucleus (center) of the atom ○ Electrons are outside the nucleus in zones called shawls ● Valence Electrons - electrons that occupy the outermost regions, those farthest from the nucleus, of an atom ○ They are the part of the atom that are involved in chemical reactions Lesson 3: Elements ● Element - a substance that is composed of a single type of atom ● Atomic Number - the number of protons for an atom of a given element ○ For neutral atoms of a given element, the atomic number also gives the total number of electrons found within the electron cloud Lesson 4: Compounds
● The electrons that an atom gains or loses when forming an ion are always the valence electrons Lesson 10: Types of Bonds ● Ionic Bond - when a strong, attractive force occurs between the two ions because one is positively charged and the other is negatively charged, and the unlike charges are attracted to one another ○ Electrons are transferred when an ionic compound forms ○ The ratio of elements in any given ionic compound is always the same ○ An ionic compound typically forms between a metal and a nonmetal ● Covalent Bond - when two nonmetals react, neither one fully transfers electrons to the other; instead, the sharing of electrons provides the attractive force that holds the atoms together ○ Shares valence electrons ○ Identity of the atom does not change ○ A molecule forms when electrons are shared in a covalent bond ○ A molecule can consist of more than two atoms ○ Not all molecules are compounds ● Metallic Bond - when metal atoms are bonded, the valence electrons move about freely from one metal atom to another ○ When metal atoms are bonded, the valence electrons move about freely from one metal to another in what is described as an “electron sea” Lesson 11: Arrangement of the Periodic Table ● Period - a row ● Group - a column ● Family - elements within a group that have the same number of valence electrons ○ With the exception of hydrogen, elements in the first column are all metals ○ Elements in column 17 are all nonmetals ○ Elements in the last column, 18, are nonmetals that almost never react at all Lesson 12: Metals, Nonmetals, and Metalloids ● Metals - atoms that tend to lose electrons ○ tend to lose electrons ○ Metals are good conductors of electricity ○ Metals are good conductors of heat ○ The ability to be stretched into wire is called ductility ○ The ability to be shaped by pounding without breaking apart is called
malleability ● Nonmetals - have electrons that are very tightly associated with the nucleus ○ Poor conductors ○ May be solid, liquid, or gas at room temperature ● Metalloids - Are shiny like metals but have an intermediate electrical conductivity, and are called semiconductors ○ Semiconductors are used in cell phones and computers and other electronic devices Lesson 13: Conservation of Matter and Physical Changes Lesson 14: Conservation of Mass and Chemical Changes ● Law of conservation of matter - matter cannot be created or destroyed Lesson 15: Chemical Equations ● Numbers called coefficients are used to indicate the ration of chemicals that participate in a reaction ○ Before the equation ● Subscripts indicate the ratio of atoms in a compound Lesson 16: Particles of Matter are in Constant Motion ● Temperature is a measure of the average kinetic energy per particle of matter ● As the average speed of particles of matter increases, so does the temperature Lesson 17: Thermal Energy ● For a gas, the thermal energy is the total kinetic energy of all the particles that make up the gas ● For a solid or liquid, the thermal energy includes both the kinetic energy and any potential energy from the interacting particles ● Heat is energy that is transferred Lesson 18: Phase Changes ● Phase change - a change from one state to another ● Evaporation - liquid turns to gas ● Condensation - gas turns to liquid ● Melting - solid turns to liquid ● Freezing - liquid turns to solid Lesson 19: Heat Transfer in Phase Changes
