6th Grade Vocabulary by Chapter

Sixth Grade

Chapter 1

Analyze – to separate into parts so you can find out the meaning, purpose, or function of the whole

Conclusion –the end or last part of a series of steps where a thoughtful judgment or opinion is stated

Confirm – to make sure or prove something is the truth

Critical Thinking – comparing what you already know with new information to decide whether you agree with it

Hypothesis – a possible explanation of an observation that can be scientifically tested

Inference – a logical explanation that uses your prior knowledge or experience

Observation – using your senses to gather information

Opinion – a belief based on your experience or knowledge; not necessarily factual

Prediction – a statement of what will happen next in a series of events

Science – the investigation and exploration of natural events and the new information that comes from the investigation

Scientific Inquiry - a logical way to investigate and suggest explanations for what is observed; a hypothesis is suggested, data is gathered and recorded, and a conclusion is made; also called the Scientific Method

Scientific Law – a rule that describes a pattern in nature; it is known to happen every time

Scientific Theory – a suggested explanation of natural events that is based on many observations and investigations; not proven true yet

Skeptical – not convinced; doubting, questioning


Chapter 2

Atom – a tiny building block of matter

Cause – a reason for a result; makes something happen

Chemical Change – a change in matter where there is a rearrangement of atoms to produce something new with different chemical and physical properties 

Chemical Formula – a short way of showing the elements and number of atoms of each element in a substance

Compound – a substance made of two or more elements that are chemically joined in a specific way

Effect – anything that happens as a result of cause, influence, or action

Element – a pure substance made of only one kind of atom

Heterogeneous – made of different, unrelated, or unlike parts; not the same

Homogeneous – made of the identical parts or structures; uniform

Identify – to show to be a certain person, thing, or association; name, describe, explain

Law of Conservation of Mass – the total mass of what goes into a chemical reaction is the same as the mass of what comes out of the reaction; mass of the reactants equals the mass of the products

Matter – anything that has mass and takes up space

Mixture – matter that can vary or change in composition

Molecule – two or more atoms that are held together chemically and act as a unit

Physical Change – a change in size, shape, form, or state (solid or liquid or gas) to another without a change in chemical composition; often reversible

Precipitate – a solid that forms when two liquids are mixed

Substance – matter with a chemical composition that is always the same


Chapter 3

Boiling Point – temperature at which a liquid becomes a gas

Color – what the eye sees as reflected light

Density – the mass per unit of volume

Differentiate – to demonstrate the differences between things

Ductile - capable of being stretched into wire or thread without breaking

Flammability – how easily something is set on fire or burns quickly

Fluorescence – the ability to produce and/or the visible light given off by a substance during exposure to ultra violet light (black light) or x-rays

Hardness –how well a mineral resists being scratched

Luster – the way the surface of a mineral reflects or absorbs light

Malleable – can be hammered or rolled into sheets without breaking; bendable

Mass – the amount of matter in an object; often referred to as weight

Melting Point - temperature at which a solid becomes a liquid

Metal – an element that is usually shiny, is easily pulled into wires or hammered into sheets, and is a good conductor of electricity or thermal energy (heat)

Metalloid – an element that shares some chemical and physical properties of metals and non-metals

Nonmetal – an element that has no metallic properties; an element that is dull, easily broken, and is a good insulator (does not conduct electricity or thermal energy)

Physical Property - characteristics of a substance that can be observed or measured without changing the composition ex. mass, volume, density, solubility, melting and boiling point, malleability, ductility, conductivity

Solubility – the ability of one material to dissolve in another

Streak – the color of a mineral when it is in powdered form

Texture – the way matter feels when you touch it

Volume – the amount of space a sample of matter occupies


Chapter 4 Vocabulary (2 parts)

Alternative – A different possibility

Biomass – Organic matter such as wood, food, scraps, and alcohol that can be burned as fuel

Geothermal – Earth’s warm interior

Hydroelectric – Electricity made by using the energy of moving water

Inexhaustible – cannot be used up

Nonrenewable Resource – a natural resource that is being used faster than it can be replaced by the processes that created it

Nuclear Energy – energy that is stored in and released from the nucleus of an atom

Pollution - a substance or thing that has harmful or poisonous effects

Reclamation – the process of restoring mined land with soil and replanted vegetation

Renewable Resource – a natural resource that can be replenished by nature as quickly as it is used

Solar Energy – energy from the Sun

Wind Farm – an area with many wind turbines to produce electricity

Unit 4 (part 2) Vocabulary

Chemical Energy – Energy that is stored in and released from the bonds between atoms

Elastic Energy - Energy that is held when materials stretch or compress

Electric Energy - Energy carried by an electric current

Energy – The ability to cause change

Energy Transformation - The process of changing one form of energy to another

Joule - A unit equal to the work when a 1 Newton force moves something a distance of one meter.

Kinetic Energy – Energy due to motion

Law of Conservation of Energy – States that energy can be transformed from one form to another, but it cannot be created or destroyed

Mechanical Energy - Sum of the potential energy and the kinetic energy in a system, the energy of moving parts

Potential Energy –The energy of things waiting to move, the energy of being still

Radiant Energy – Energy carried by an electromagnetic wave (often thought of as light or solar)

Sound Energy – Energy carried by sound waves

Thermal Energy – The total of the energies of moving and still particles that make up an object

Work - The amount of energy used as a force moves an object over a distance

Chapter 5 Vocabulary

Acceleration – a measure of how quickly the velocity of an object changes

Air Resistance – the force of friction between air and objects moving through it

Contact Force – A force that directly touches an object

Displacement – the difference between the initial (starting) position and the final position (end)

Force – a push or pull on an object

Friction – a contact force that resists the sliding motion of two touching surfaces

Gravity – an attractive force that exists between all objects that have mass

Motion – the process or act of changing position

Noncontact Force – A force that does not touch another object, yet still affects the object

Position – Describes an object’s distance and direction from a reference point

Reference Point – The starting point you choose to describe the location or position of an object

Speed – the distance an object moves in a unit of time

Velocity – the speed and direction of a moving object


Chapter 6

Conduction – the transfer of thermal energy (heat) by collisions between particles in matter (touching)

Contract – to decrease in size, number, or range

Convection – the transfer of thermal energy by the movement of the particles from one part of a material to another

Equilibrium - a state in which opposing forces or influences are balanced

Expand – to become or make larger or more extensive

Heat – the movement of thermal energy from a region of higher temperature to a region of lower temperature

Radiation – the transfer of thermal energy (heat) by electromagnetic waves

Sublimation – the change of state that occurs when a solid changes to a gas without passing through the liquid phase

Temperature – the measure of the average kinetic energy of the moving particles in a material.

Thermal conductor – a material in which thermal energy moves quickly

Thermal insulator – a material in which thermal energy moves slowly

Vaporization – the change of state from a liquid to a gas

Chapter 7

Asthenosphere – The partially melted portion of the mantle below the lithosphere

Convection – The circulation of material caused by differences in temperature and density

Convergent Boundary – The boundary between two plates that move toward each other

Core – the dense, metallic center of the Earth

Crust – The brittle, rock outer layer of Earth

Density – The mass per unit volume of a substance

Divergent Boundary – The boundary between two plates that move away from each other

Geosphere – The solid part of the Earth

Gravity – an attractive force that exists between all objects that have mass

Lithosphere – The rigid outer layer of Earth that includes the uppermost mantle and crust

Magnetosphere – The outer part of Earth’s magnetic field that interacts with charged particles to protect the planet

Mantle – The thick middle layer in the solid part of Earth

Plastic – soft enough to flow

Plate Tectonics – The theory that Earth’s surface is broken into large, rigid pieces that move with respect to each other

Seismic - relating to earthquakes or other vibrations of the Earth and its crust

Sphere – a shape like a ball where all points are equal distance from the center

Subduction – The process when one tectonic plate moves under another tectonic plate

Transform Boundary – The boundary between two plates that slide past each other


Chapter 8

Rock – a naturally occurring solid composed of mineral, rock fragments, and sometimes other materials such as organic matter

Sediment – rock material that forms when rocks are broken down into smaller pieces or dissolved in water as rocks erode

Rock Cycle – the series of processes that change one type of rock into another type of rock

Extrusive Rock – Igneous rock that forms when volcanic material erupts, cools, and crystallizes on Earth’s surface; crystals are small

Intrusive Rock – Igneous rock that forms as magma cools underground; crystals are large

Volcanic Glass – rock that forms when lava cools too quickly to form crystals

Compaction – a process in which the weight from the layers of sediment forces out fluids and decreases the space between sediment grains

Cementation – a process in which minerals dissolved in water crystallize between sediment grains

Foliated Rock – metamorphic rock that contains parallel layers of flat and elongated minerals

Nonfoliated Rock – metamorphic rock with mineral grains that have a random, interlocking texture

Grain – an individual particle in rock

Conglomerate – Sedimentary rock formed from rounded gravel naturally cemented together; the rounding of the gravel indicates that the rock has been transported a long way from the original source


Chapters 9 and 10

Asteroid – a small rocky object that orbits the Sun between Mars and Jupiter

Comet – made of gas, dust, and ice.  Orbits the Sun in an oval-shaped path

Meteor – a streak of light in Earth’s atmosphere made by a glowing meteoroid

Meteoroid – a small rocky particle that moves through space

Meteorite – a meteoroid that strikes the surface of a planet or moon

Galilean Moon – the four largest moons of Jupiter (Io, Europa, Ganymede, and Callisto)

Rocket – a vehicle designed to propel (launch) itself by ejecting exhaust gas against a launch surface

Satellite – ANY object that orbits another larger object

Space Probe – an uncrewed spacecraft sent from Earth to explore objects in space

Lunar – a term referring to anything that has to do with the Moon

Space Shuttle – a reusable spacecraft that transports people and materials to and from space

Astronomical Unit (A.U.) – the average distance from Earth to the Sun (about 150 million kilometers)

Greenhouse Effect – The result of a planet’s atmosphere trapping solar energy and causing the surface temperature of the planet to increase

Rotation - a turning around on an axis, spin

Revolution - the movement of one object around a center or another object

Chapter 11

Abiotic – a nonliving thing in an ecosystem

Autotroph – an organism that converts light energy to usable energy

Biotic – a living or once-living thing in an ecosystem

Cell Membrane – protects the inside of the cell from the external environment

Community – all the populations living in an ecosystem at the same time

Cytoplasm – the liquid part of cell inside the cell membrane

Domain – the broadest level of classification; includes evolutionary links between organisms

Ecosystem – all the living and nonliving things in a given area

Eukaryotic – cells with a nucleus and other membrane enclosed organelles

Habitat – the place within an ecosystem where an organism lives; provides the biotic and abiotic factors an organism needs to survive and reproduce

Heterotroph – an organism that obtains energy from other organisms

Kingdom – a focused level of classification based on cellular structure/organization and mode of getting food

Mitochondrion – an organelle in a cell that breaks down food and releases energy

Multicellular – composed of many types of cells working together

Nucleus – an organelle which stores genetic information contained within a cell membrane; found in eukaryotes

Organelle – a part of a eukaryotic cell with a special function and is surrounded by a membrane

Population – all the organisms of the same species that live in the same area at the same time

Prokaryotic – a cell that does not have a nucleus or other membrane surrounded organelles

Ribosome – produces proteins for a cell

Unicellular – a living organism made of a single cell

Vacuole – an organelle that stores water, waste, or food