Science TAKS vocabulary

Question Answer
Hypothesis a testable explanation or prediction
Conclusion summarizing the data and results of an experiment and either accepting or rejecting the hypothesis
Independent Variable the variable that we change to see the effect it will have on the dependent variable (example: amount of water )
Dependent Variable the variable that we are studying to see how it is affected by a change in some other variable (example:height of plants)
Controlled Variables variables that are kept constant so that the changes that we observe are only due to the independent variable that we change
Data the observations made in an experiment
Model a simple or abstract way of representing something. Example: used to describe atoms
Topographic Map a map that shows the surface features or elevation of an area
Mass the measure of the amount of matter in an object. (Instrument-balance) (Unit is grams) ( NEVER CHANGES)
Volume the measure of the amount of space an object takes up. (Instrument-graduated cylinder or ruler) (unit is ml or cm3)
Density the amount of matter squeezed into a certain space. (unit- g/ml or g/cm3). Physical Property
Cells the smallest unit of life found in ALL living organisms
Unicellular made of one cell
Multicellular made of many cells
Cell Membrane outer covering found in ALL cells
Cell Wall rigid outer covering found in plants
Nucleus structure in cell where DNA or chromosomes are found
Cytoplasm fluid that fills the cell
Mitochondrian organelle in the cell where glucose is converted into energy that cells can use (respiration)
Chloroplasts structures in plant cells that contain chlorophyll which traps sunlight for photosynthesis
Respiratory system where gases can enter and exit the body. (Main organ: lungs(trachea
Digestive system where food is broken down into nutrients that can be absorbed into the blood stream
Circulatory systems where oxygen
Nervous systems where the nerves and brain control the bodies activities.
Muscular system responsible for movement (muscles are attached to bones)
Skeletal system responsible for support
Excretory system responsible for removing wastes (organ-kidneys filter waste from blood)
Endocrine system of ductless glands that secrete hormones which regulate activities such as growth and metabolism
Integumentary system that includes skin/hair/and nails
Lymphatic system that provides and cleans the fluid found between cells. (Organ- tonsils) (lymph glands are swollen during infection)
Reproductive system responsible for producing offspring. (gametes-eggs and sperm)
Immune system responsible for fighting infection (white blood cells and antibodies) (vaccines cause us to produce antibodies)
Homeostasis the process of maintaining a balance
Equilibrium the state of having a balance
Feedback a mechanism for maintaining equilibrium. Examples: Pancreas secreting insulin to regulate blood sugar or sweating when warm
Adaptations structures or behaviors that increases an organisms chance for survival
Chromosomes structures in nucleus where DNA is located
Genes a part of a DNA molecule that has the information for one trait
Alleles a form of a gene that we get from each parent
Dominant the allele that covers up another allele so that its trait get expressed
Recessive the allele that gets covered up by another allele
Homozygous both alleles are the same ( BB or bb)
Heterozygous both alleles are different (Bb)
Traits our physical and behavioral characteristics that we inherited from our parents
Punnett Square used to predict the probability of getting certain genotypes or phenotypes
Probability the chance of a certain outcome usually expressed as a percentage
Photosynthesis process where plants use carbon dioxide and water to make glucose and oxygen
Food Web shows the interrelationships between organisms in terms of the movement of energy through an ecosystem
Producer organisms that make their own food (plants)
Consumer organisms that feed on other organisms
Decomposer organisms that feed on the remains or dead organisms and breaks down organisms so nutrients can be recycled
Energy Pyramid model that represents the amount of energy/biomass at each trophic level. Only 10% of energy moves up to next level. The rest is lost as heat
Primary Succession the change from barren rock to an area with vegetation usually after volcanic eruption or removal of soil. (lichens break rock down into soil)
Secondary Succession the change that occurs after an establish forest has been destroyed but there is still soil and life forms present (fire)
Atom the smallest piece of an element
Proton particle in the nucleus of an atom with a positive charge
Neutron particle in the nucleus of an atom that does not have a charge
Electron particle found outside of the nucleus (shell/cloud) and has a negative charge
Atomic Number the number of protons in an atom (also electrons)
Isotopes atoms of the same element such as hydrogen but with different numbers of neutrons
Mass Number the number of both protons and neutrons in an atom
Periodic Table a way of organizing all of the elements found in the universe
Periods horizontal rows on the Periodic Table (The period number is the number of shells)
Groups/Families vertical columns on the Periodic Table where elements have similar chemical properties.
Valence Electrons the number of outer electrons in an atom. (It is the Group Number for the Main Elements) 1/2/3b…8b
Metals elements on the LEFT side of the Periodic Table that are usually soft/shiny/malleable/ductile/low specific heat/high melting points/good conductors
Non-metals elements on the RIGHT side of the Periodic table that are usually dull
Transition Metals elements in the middle of the Periodic Table
Metalloids elements along the zig zag stair case that have properties of both metals and nonmetals
Element a substance made up of only one atom
Compound a substance made up of two or more elements that have been chemically combined
Mixture two or more substances brought together but are not combined chemically and still keep their same properties
Matter anything that has mass and takes up space
States of Matter solid/liquid/gas/plasma
Solid has a definite shape and definite volume
Liquid has a definite volume but not a definite shape
Gas does not have a definite shape or volume
Plasma a gas at high temperatures where it has become electrically charged (lightning/fluorescent lights/Auroras/stars)
Physical Changes a change where the material keeps it's same properties such as tearing
Evaporation physical change where a liquid becomes a gas (usually due to increasing temperature)
Condensation physical change where a gas becomes a liquid (usually due to cooler temperatures)
Chemical Changes change where a substance is changed into a new substance with new properties after a chemical reaction
Physical Properties properties that describe the appearance of a substance such as color/shape/texture/luster/melting point/mass/density/etc.
Texture the surface features of a substance (smooth/rough) Physical Property
Luster describes how a substance reflects light (shiny/metallic/dull)
Physical Property describes the appearance of a material
Ductile physical property of metals being pulled or stretched into wire without breaking
Malleable physical property of metals being hammered into sheets or bent into different shapes without breaking
Mass the amount of matter in an object (measured with a balance) (unit is gram) Does not change
Volume the amount of space an object takes up (measured with graduated cylinder or ruler) (units are ml or cm3)
Density the measure of how squeezed together particles are in an object ( units are g/ml or g/cm3)
Melting Point the temperature at which a solid changes to a liquid
Boiling Point the temperature at which a liquid changes to a gas
Chemical Properties properties that describe how a substance will react chemically with another substance
Flammability the ease atwhich a material will burn
Corrosive the ability of a substance to destroy another substance through a chemical reaction (acids corrode metals)
Reactivity the degree that a substance will react chemically
Toxicity the degree that a substance can damage an organism
Subscript the number written below an element that indicates the number of atoms present (example H2O)
Coefficient the number written in front of a formula that indicates the number of molecules that are present (example 3HCl)
Law of Conservation of Mass the mass of the reactants will be the same as the mass of the products. Matter is not created or destroyed.
Reactants the substances on the left side of an equation involved in the reaction
Products the substances on the right hand side of an equation that are formed in a reaction
Exothermic a reaction where heat is released ( the beaker gets hot)
Endothermic a reaction where heat is absorbed (the beaker gets cold)
Chemical Bond the force of attraction that holds atoms together in compounds or molecules
Signs of a Chemical Reaction color change/new odor/bubbling/temperature change/solid precipitate
Energy the ability to do work(mechanical/heat/chemical/electromagnetic/nuclear) (units are Joules)
Work is done anytime a force moves an object (units are Joules or Newton/meters)
Kinetic Energy energy of motion (depends on mass and velocity)
Potential Energy energy of position (depends on mass and height) (can also depend on the distance a spring is stretched)
Waves a repeated disturbance in matter that transfers energy
Reflection a wave striking an object an bouncing back at the same angle
Refraction the bending of waves because they are entering a different substance (a spoon appearing bent or eyeglasses correcting vision)
Compression the part of a sound wave(longitudinal) where matter is squeezed together/more dense
Rarefaction the part of a sound wave (longitudinal) where matter is spread out/less dense
Forces anything that causes a change in speed or direction of an object (any push or pull) (units are Newtons)
Speed the rate at which an object changes its position (distance divided by time) d/t
Velocity the speed and direction of an object ( 60mi/hr North )
Acceleration the rate at which an objects changes its velocity (Final velocity – Initial Velocity)/(divided by the time)
Friction a force that opposes motion (drag)
Machine a device that helps us do work by changing the size or direction of a force. Simple Machines are lever/screw/inclined plane/wheel and axle/pulley/wedge
Lunar Eclipse a celestial event where the Earth blocks the sunlight casting a shadow on the Moon.
Solar Eclipse a celestial event where the Moon blocks the sunlight casting a shadow on PART of the Earth
Moon Phases occurs because we see the part of the Moon that is lit by the Sun. New/Waxing Crescent/1st Quarter/Waxing Gibbous/Full(2nd)/Waning Gibbous/3rd Quarter/Waning Crescent/New
Waning a smaller amount of the Moon is becoming visible each day.
Waxing a larger amount of the Moon is becoming visible each day
Seasons the changes in temperature due to the angle that the sunlight strikes the Earth because of its tilt while revolving around the Sun.
Inner Planets Mercury/Venus/Earth/Mars (Rocky)
Outer Planet Jupiter/Saturn/Uranus/Neptune/Pluto? (Gaseous)
Asteroids smaller solar system bodies (Many are found between the Outer and Inner Planets
Nebulae clouds of gas
Galaxies a system that contains millions to trillions of Stars along with gas/dust/and Dark Matter (Our Milky Way Galaxy is a Spiral Galaxy)
Light year the distance that light travels in one year (Our closest star from our Solar System is over 4 light years away)
Rock Cycle the process where rock can be changed and reformed
Sedimentary rock formed from sediment that is cemented and compacted (example sandstone and shale)
Metamorphic rock formed from heat and pressure (example Gneiss and Slate )
Igneous rock formed from melting and cooling
Weathering the breaking down of rock material by water/frost action/wind/plant roots/and other forces
Erosion the carrying or transporting of loose rock material/soil
Deposition the accumulating or settling of loose rock/soil materialPlate Tectonics
Converging two plates moving together (can form Mountains when Continental Plates collide)
Diverging two plates moving apart (Sea floor spreading can form Ocean Ridges)
Transform two plates moving side by side (typically cause earthquakes/San Andreas Fault)
Water Cycle the process of water changing states as it moves through the Earth's surface and troposphere (evaporation/condensation/precipitation/runoff)
Surface Water water found on the ground or in streams/rivers/lakes/or oceans
Ground water water trapped in the spaces of soil and rock.
Aquifer water found in the spaces of rocks and sediment that can readily be pumped by wells or charge a Spring.
Nitrogen Cycle the process of nitrogen in the air being fixed by bacteria for use in plants and bacteria releasing nitrogen from the remains of dead organisms back into the air (Our nitrogen comes from plants or eating animals that eat plants)
Nitrogen Fixation the process of bacteria converting atmospheric nitrogen into compounds that can be absorbed into plants.
Carbon Cycle the process of carbon moving through an ecosystem (Photosynthesis
Photosynthesis process of plants using carbon dioxide and water to make glucose and oxygen
Respiration the process of animals converting glucose into energy in the mitochondrian of cells and releasing carbon dioxide as a waste
Greenhouse Effect the phenomenon of gases in the atmosphere trapping heat that is being reflecting from the Earth causing our planet to be warm.
Ozone a layer of oxygen molecules in the Stratosphere that absorbs ultraviolet radiation from the Sun. CFC's are chemicals found in aerosols and refrigerents that can destroy this layer.
Renewable resources that can be produced by the Earth faster than we consume (wood/water/food/biomass)
Nonrenewable resources that can not be produced by Earth faster than we consume (oil/coal)
Exhaustible resources that we can run out of (coal/oil/uranium)
Inexhaustible resources that we will not run out of (solar/wind/tidal/geothermal)
Evaporation the process of a water changing to water vapor
Condensation the process of water vapor from water (clouds)
Precipitation the process of sleet