Physics
The study of forces, energy, motion
Chemistry
The study of atoms and molecules, their structures, and their interactions to form
... [Show More] substances
Earth science
The study of the Earth's structure and composition, and processes that change Earth
essential attributes of science
Studies the natural world
Uses testable ideas
Relies on data from observations/experiments
Presented for evaluation by other scientists
Leads to further questions/research
variables
The changing quantities in an experiment
independent variable
What you change in an experiment on purpose
dependent variable
The variable that changes because of an independent variable
control variable
The variable(s) you don't want to study, need to be either eliminated or kept constant
observational study
When systems are observed as they appear in nature, researchers do not attempt to change them
physical model
A model of a physical phenomenon, such as a planetary system
conceptual model
A model used to visualize things that cannot be seen, such as atoms
mathematical model
A model that treats physical objects/phenomena using mathematical methods
computer model
A detailed, complex model calculated by a computer
principle of falsification
Principle that 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, describes a widespread pattern in nature (what)
theory
A statement that explains a wide range of observations, supported by a large body of scientific evidence (how/why)
meter
Base unit of length
kilogram
Base unit of mass
second
Base unit of time
kelvin
Base unit of temperature
Derived units
What is produced when the base units/quantities are combined
Speed
The name for the distance traveled divided by an interval of time
Volume
Term for the amount of space an object occupies
Liquid displacement
Method of determining the volume of an object by measuring the amount of liquid it displaces
direct relationship
A relationship between two variables where increasing one increases the other, and vice versa
inverse relationship
A relationship between two variables where increasing one decreases the other, and vice versa
Velocity
A combination of speed and direction
Acceleration
Term for any change in an object's speed and/or direction
Force
Term for a push or a pull with direction and magnitude. You may not feel it.
Net force
The sum of all forces acting on an object
balanced forces
Term for forces that combine to produce a net force of 0
Newton's first law
An object in motion remains in motion unless acted on by a net force
inertia
The tenancy to keep the same motion/velocity or remain at rest. Newton's first law
Newton's second law
Net force = mass x acceleration (F = ma)
Newton's third law
When 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 ("For every action, an equal and opposite reaction")
friction
The force that opposes the motion of an object on which it acts
Kinetic friction
Friction between two objects moving against each other
Static friction
Friction between two objects touching but not moving against each other
Fluid resistance
Friction when an object moves through a gas or liquid
Gravity
Attractive force between objects directly proportional to their masses and inversely proportional to the square of their distance
Linear momentum
Name for the mass of an object times its velocity
Law of conservation of momentum
Term for the fact that momentum is conserved when two or more objects collide
elasticity
The amount of bounce an object has after a collision
Elastic collision
A collision in which the total kinetic energy is conserved
Inelastic collision
A collision in which the total kinetic energy is not conserved
Work
Term for the displacement of an object in the direction of an applied force by using/converting energy
Energy
The capacity to do work or cause change
Kinetic energy
The energy objects have because they are moving. Increases with mass and velocity
potential energy
Energy that is stored
Formula for work
work = force x displacement
gravitational potential energy
Energy an object has due to its height above the ground. Increases with mass and height.
chemical potential energy
Energy that is stored in the chemical bonds in a substance
elastic potential energy
Energy stored in stretched springs, rubber bands, etc.
electromagnetic energy
Energy carried by electromagnetic waves. Light energy.
thermal energy
Energy from the motion of atoms and molecules. Depends on mass and temperature
Law of conservation of energy
Term for the fact that energy cannot be created/destroyed, only transferred/converted
oscillation
A repetitive motion that occurs around a center point or equilibrium
equilibrium
A position or state to which an oscillating object eventually returns to
wave
A repeating and periodic disturbance (oscillation) that travels from one point to another, transferring energy
mechanical waves
Type of waves that require a medium (air, water, etc.) to travel through, cannot travel through a vaccuum
transverse wave
Wave where the oscillation is perpendicular to the direction the wave is traveling
longitudinal wave
Wave where the oscillation occurs along the direction the wave is traveling
electromagnetic waves
Waves with both an electric and magnetic component. Can only be transverse waves and can travel through a vaccuum
compression
Region of longitudinal wave where particles are close together
expansion
Region of longitudinal wave where particles are far apart (aka rarefaction)
crest
The highest point in a wave above equilibrium
trough
The lowest point in a wave under equilibrium
amplitude
The distance between a wave's equilibrium and crest/trough in a transverse wave, or how compressed/expanded the medium becomes in a longitudinal wave
wavelength
The horizontal distance after which the wave repeats
period
The amount of time needed for one full oscillation/one wave to pass
frequency
Number of wave oscillations in a given period of time
sound wave
A disturbance we can hear that moves through a medium away from the source
Matter
Anything that takes up space and has mass
Atom
The basic building block of matter
valence electrons
The electrons in the outer most shell of an atom
Element
A pure substance made of only one kind of atom, defined by its proton count
atomic number
The number of protons in the nucleus of an atom
Chemical
Any substance that has a definite, fixed composition
Compound
a chemical combination of two or more different elements in a fixed ratio
chemical bonds
the attractive forces that hold atoms together
organic compound
Compounds that contain carbon and hydrogen
Inorganic compounds
Compounds that are not organic compounds
pure substance
A chemical containing only one type of element or compound
Mixture
A combination of two or more substances that are not chemically combined and not present in a specific, fixed ratio
heterogeneous mixture
A mixture in which pure substances are unevenly distributed throughout the mixture
homogeneous mixture
A mixture in which substances are evenly distributed throughout the mixture
macroscopic properties
The properties observed when a large number of particles interact
microscopic properties
Properties at the small scale, such as properties of atoms and molecules
Troposphere
The lowest layer of Earth's atmosphere where weather occurs
Stratosphere
the layer above the troposphere; the ozone layer is found in this layer, planes fly here
ozone layer
Protective layer in atmosphere that shields earth from UV radiation.
Mesosphere
The layer of Earth's atmosphere immediately above the stratosphere, where meteors burn up
Thermosphere
The atmospheric layer above the mesosphere where auroras occur, ISS orbits here
Exosphere
The outer layer of the atmosphere
physical change
When matter changes in appearance without changing in chemical composition
chemical change
When matter changes in chemical composition
chemical reaction
When chemical bonds are formed/broken in a chemical change
Reactants
The substances present before a chemical reaction begins
Products
The substances formed during a chemical reaction
Ion
An atom with a net electric charge (i.e., not neutral)
ionic bond
Chemical bond formed between a positively charged atom and a negatively charged atom, where a valence electron is given from one to the other
ionic compound
Compounds formed via ionic bonds, usually a combination of a metal and one or more non-metals
covalent bond
Bond formed between atoms that share valence electrons
metallic bond
Bond formed between atoms of metals using an electron sea where valence electrons move about freely
period
Name for a row in the periodic table
group
Name for a column in the periodic table
family
Name for elements in the same group of the periodic table that have the same number of valence electrons
metals
Term for elements that tend to lose electrons
malleability
The ability to be shaped by pounding without breaking apart
ductility
The ability to be stretched into wire
nonmetals
Term for elements with electrons very tightly associated with the nucleus
metalloids
Term for elements that are shiny like metal but have intermediate electrical conductivity (i.e. semiconductors)
law of conservation of matter
Term for the fact that matter cannot be created/destroyed, but can be converted between forms through physical or chemical changes
coefficient
Number used to indicate the ratio of chemicals in a reaction, written before chemical formula
Temperature
Term for the measure of the average kinetic energy per particle
Thermal energy
Term for the total energy in the particles of an object
nebula
A cloud of gasses and particles
nuclear fusion
Process where hydrogen and other nuclei fuse together into larger nuclei
star
Celestial body that held together by its own gravity that releases 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
asteroids
Very small, rocky bodies that orbit the sun
moon
A naturally formed object that orbits a planet
comets
Relatively small, icy, dusty bodies that travel around the sun in very elliptical orbits
crust
Thin, outermost rocky shell at the surface of the earth
mantle
Thickest layer of the Earth made of hot, solid rock, 84% of volume of the planet
outer core
Outer half of the Earth's core. Made of mostly molten iron
inner core
Inner half of the Earth's core. Made of solid nickel-iron
weathering
The alteration or breakdown of rock or soil
physical weathering
Weathering resulting from mechanical processes
chemical weathering
Weathering resulting from chemical processes
erosion
The mechanism responsible for the transportation or removal of material
glacier
A slowly moving mass of ice formed by the accumulation and compaction of snow that flows slowly over time
deposition
The process in which soil, sediment, or rocks are added to a landform
meanders
Curves in a river formed by eroding the outer bank and depositing sediment on the inner bank
mineral
A naturally occurring, solid inorganic element/compound formed by natural processes, with a limited range of possible chemical composition and a definite arrangement of atoms
sedimentary rocks
Rocks made up of weathered particles (sand, silt, clay, gravel, cobbles, or even boulders) that have been cemented together into hard rock
igneous rocks
Rocks formed by lava or magma
metamorphic rocks
Rocks formed through heat and pressure which causes their minerals to change
rock cycle
Name for the various processes that change rocks from one form to another
Precambrian Era
Era consisting of Hadean, Archean, and Proterozoic eons
4 eons
Hadean, Archean, Proterozoic, and Phanerozoic
Paleozoic era
Era consisting of greatest diversification of life on earth
Mesozoic era
Era when the dinosaurs thrived
Cenozoic era
Current era, the age of mammals
principle of superposition
Principle stating in undeformed sedimentary rocks, each bed is younger than the one below it
principle of crosscutting relationships
If a rock, fault, or other feature cuts through a rock layer, that rock layer must have been pre-existing in order to have been cut through. Determines relative ages of different rocks
unconformity
A buried erosional surface, suggesting a lack of information
convergent boundary
A tectonic plate boundary where the plates push into each other, causing large quakes
divergent boundary
A tectonic plate boundary where the plates are separating, with volcanoes and few, weak quakes [Show Less]