physical-science Vocabulary
JamWise Education Team·Updated March 2026
The physical-science strand is a core part of the K-8 science curriculum. It encompasses 121 vocabulary terms that students encounter as they progress from kindergarten through 8th grade. Each term builds on previous knowledge, creating a spiral of deepening understanding that prepares learners for increasingly complex concepts.
Understanding physical-science vocabulary is essential for classroom discussions, assessments, and real-world application. Below you will find every term organized by grade level, so teachers and parents can quickly identify which words are appropriate for their students and explore definitions tailored to each developmental stage.
Kindergarten
(16 terms)
Air
Air is all around us even though we cannot see it. Air is a gas we breathe.
Cold
Cold means having a low temperature. Ice and snow are cold.
Compare
To compare means to look at two or more things and find what is the same and what is different.
Float
To float means to stay on top of a liquid. A rubber duck floats on water.
Hot
Hot means having a high temperature. Fire and the sun are hot.
Light
Light lets you see things. The sun and lamps give off light.
Liquid
A liquid flows and takes the shape of its container. Water and juice are liquids.
Motion
Motion is when something moves from one place to another.
Observe
To observe means to watch something carefully and notice what happens.
Pull
A pull moves something toward you.
Push
A push moves something away from you.
Sink
To sink means to fall to the bottom of a liquid. A rock sinks in water.
Solid
A solid keeps its shape. A block and a rock are solids.
Sound
Sound is what you hear when something vibrates. Clapping your hands makes a sound.
Vibration
A vibration is a fast back-and-forth movement that can make sound.
Wet
Wet means covered with or soaked in water or another liquid.
1st Grade
(8 terms)
Force
A force is a push or a pull that can make something move, stop, or change direction.
Gas
A gas is matter that spreads out to fill any space. Air is a gas you cannot see.
Gravity
Gravity is an invisible force that pulls everything down toward the ground.
Magnet
A magnet is an object that can pull certain metals toward it.
Material
A material is what something is made of, like wood, metal, plastic, or cloth.
Properties
Properties are the things you can observe about an object, like its color, shape, size, and texture.
Reflect
To reflect means to bounce light off a surface. A mirror reflects light.
Shadow
A shadow is a dark shape made when an object blocks light.
2nd Grade
(6 terms)
Absorb
To absorb means to soak up a liquid. A sponge absorbs water.
Energy
Energy is the power that makes things work, move, or change. Light, heat, and sound are types of energy.
Flexibility
Flexibility is how easily something can bend without breaking.
Heat
Heat is energy that makes things warmer. The sun gives off heat.
Matter
Matter is anything that takes up space and has weight. Everything you can touch is matter.
Texture
Texture is how something feels when you touch it — smooth, rough, bumpy, or soft.
3rd Grade
(12 terms)
Attract
To attract means to pull something closer. A magnet attracts iron and steel.
Balanced forces
Balanced forces are equal pushes or pulls on an object from opposite directions, so the object stays still.
Dissolve
To dissolve means when a solid mixes completely into a liquid so you can no longer see it.
Electric charge
An electric charge is a property of matter that causes it to push or pull on other charged objects.
Friction
Friction is a force that slows down or stops objects when they rub against each other.
Gravity
Gravity is a force that pulls objects toward each other. Earth's gravity pulls everything toward the ground.
Magnetic force
Magnetic force is an invisible push or pull created by a magnet.
Pattern
A pattern is something that repeats in a regular way. Scientists look for patterns in nature.
Repel
To repel means to push something away. Two magnets with the same pole facing each other repel.
States of matter
The three common states of matter are solid, liquid, and gas. Matter changes state when it gains or loses energy.
Static electricity
Static electricity is a buildup of electric charge on the surface of an object.
Unbalanced forces
Unbalanced forces happen when one push or pull is stronger than another, causing an object to move.
4th Grade
(13 terms)
Amplitude
Amplitude is the height of a wave. A wave with high amplitude is loud or bright; a wave with low amplitude is quiet or dim.
Circuit
A circuit is a path that electricity follows in a loop from a battery through wires and back again.
Conductor
A conductor is a material that lets heat or electricity flow through it easily. Metal is a good conductor.
Energy transfer
Energy transfer is when energy moves from one object or place to another.
Frequency
Frequency is how many times a wave repeats in one second. High frequency makes a high-pitched sound.
Insulator
An insulator is a material that does not let heat or electricity flow through it easily. Rubber and wood are insulators.
Reflection
Reflection happens when light bounces off a surface, like a mirror or still water.
Refraction
Refraction is the bending of light when it passes from one material to another, like from air into water.
Sound wave
A sound wave is a vibration that travels through air, water, or solid materials and can be heard by our ears.
Speed
Speed is how fast something moves — the distance it travels in a certain amount of time.
Vibration
A vibration is a rapid back-and-forth movement that produces sound waves.
Wave
A wave is a repeating movement that carries energy from one place to another.
Wavelength
Wavelength is the distance between the top of one wave and the top of the next wave.
5th Grade
(16 terms)
Absorption
Absorption is when a material soaks up light, heat, or sound instead of reflecting it. Dark colors absorb more light.
Acceleration
Acceleration is the change in speed or direction of a moving object.
Chemical change
A chemical change turns one substance into a completely new substance with different properties. Burning wood is a chemical change.
Conduction
Conduction is the transfer of heat through direct contact between materials.
Convection
Convection is the transfer of heat through the movement of liquids or gases in circular currents.
Force
A force is a push or a pull that can change an object's speed, direction, or shape.
Gravity
Gravity is a force that pulls objects toward each other. Earth's gravity keeps us on the ground and the moon in orbit.
Inertia
Inertia is the tendency of an object to resist changes in its motion. An object at rest stays at rest unless a force acts on it.
Mass
Mass is the amount of matter in an object. It is measured in grams or kilograms.
Mixture
A mixture is two or more substances combined together where each keeps its own properties and can be separated.
Physical change
A physical change alters the form or appearance of matter but does not turn it into a new substance. Cutting paper is a physical change.
Radiation
Radiation is the transfer of heat through waves that can travel through empty space. The sun heats Earth by radiation.
Solubility
Solubility is a measure of how much of a substance can dissolve in a liquid at a given temperature.
Solution
A solution is a mixture where one substance dissolves completely in another, like sugar dissolved in water.
Thermal energy
Thermal energy is the energy of moving particles inside matter. The faster particles move, the warmer the matter is.
Volume
Volume is the amount of space an object takes up. It is measured in liters or cubic centimeters.
6th Grade
(18 terms)
Compound
A compound is a substance made of two or more elements chemically bonded together in a fixed ratio.
Convection
Convection is the transfer of heat through the movement of a fluid, where warm fluid rises and cool fluid sinks.
Density
Density is a measure of how much matter is packed into a certain volume of a substance.
Element
An element is a pure substance that cannot be broken down into simpler substances by chemical means.
Energy
Energy is the ability to cause change or do work. It exists in many forms including heat, light, sound, and motion.
Energy conservation
Energy conservation is managing energy use wisely to avoid waste, such as turning off lights and using insulation.
Energy resources
Energy resources are sources of energy used to do work, including fossil fuels, solar, wind, and nuclear power.
Heat
Heat is the transfer of thermal energy from a warmer substance to a cooler substance.
Kinetic energy
Kinetic energy is the energy an object has because it is moving.
Metalloids
Metalloids are elements that have some properties of metals and some properties of nonmetals, like silicon.
Metals
Metals are elements that are shiny, conduct heat and electricity well, and can be hammered into shapes.
Nonmetals
Nonmetals are elements that are usually dull, poor conductors, and brittle in solid form.
Potential energy
Potential energy is stored energy an object has because of its position or condition.
Precipitate
A precipitate is a solid that forms and settles out of a liquid during a chemical reaction.
Speed
Speed is the distance an object travels divided by the time it takes.
Temperature
Temperature is a measure of the average kinetic energy of the particles in a substance.
Unbalanced force
An unbalanced force occurs when the net force on an object is not zero, causing it to accelerate.
Velocity
Velocity is a measurement of both speed and direction of a moving object.
7th Grade
(15 terms)
Atom
An atom is the smallest unit of an element that still has all the properties of that element.
Chemical reaction
A chemical reaction occurs when substances interact to form new substances with different properties.
Compound
A compound is a substance made of two or more elements chemically bonded in a fixed ratio, with properties different from its elements.
Conservation of mass
The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction — the total mass stays the same.
Electromagnetic spectrum
The electromagnetic spectrum is the full range of electromagnetic radiation, from radio waves to gamma rays, with visible light in the middle.
Element
An element is a pure substance made of only one type of atom that cannot be broken down by chemical means.
Endothermic reaction
An endothermic reaction is a chemical reaction that absorbs heat energy from the surroundings.
Exothermic reaction
An exothermic reaction is a chemical reaction that releases heat energy into the surroundings.
Mixture
A mixture is a combination of two or more substances that are not chemically bonded and can be separated by physical means.
Molecule
A molecule is two or more atoms bonded together. A water molecule is made of two hydrogen atoms and one oxygen atom.
PH scale
The pH scale measures how acidic or basic a substance is, from 0 (very acidic) to 14 (very basic), with 7 being neutral.
Product
A product is a new substance formed as a result of a chemical reaction.
Reactant
A reactant is a substance that enters into a chemical reaction and is changed.
Solubility
Solubility is the maximum amount of a substance that can dissolve in a given amount of solvent at a specific temperature.
Wave
A wave is a disturbance that transfers energy from one place to another without transferring matter.
8th Grade
(37 terms)Acceleration
Acceleration is the rate at which an object's velocity changes over time — speeding up, slowing down, or changing direction.
Atomic mass
Atomic mass is the total mass of protons and neutrons in an atom's nucleus, measured in atomic mass units.
Atomic number
The atomic number is the number of protons in the nucleus of an atom, which determines what element it is.
Chemical bond
A chemical bond is the force of attraction that holds atoms together in a molecule or compound.
Conduction
Conduction is the transfer of thermal energy through direct contact between particles of matter.
Convection
Convection is the transfer of thermal energy through the circular movement of heated fluids or gases.
Covalent bond
A covalent bond forms when two atoms share one or more pairs of electrons.
Density
Density is the mass of a substance per unit of volume, calculated as density = mass / volume.
Electric current
Electric current is the flow of electric charges (usually electrons) through a conductor.
Electromagnetic induction
Electromagnetic induction is the process of generating an electric current by moving a magnet through or near a coil of wire.
Electromagnetic spectrum
The electromagnetic spectrum is the complete range of electromagnetic radiation organized by wavelength and frequency.
Electromagnetic wave
An electromagnetic wave is a wave that can travel through empty space, carrying energy as vibrating electric and magnetic fields.
Electron
An electron is a tiny negatively charged particle that moves around the nucleus of an atom in energy levels.
Energy conservation
The law of conservation of energy states that energy cannot be created or destroyed, only transformed from one form to another.
Ion
An ion is an atom that has gained or lost electrons, giving it a positive or negative electrical charge.
Ionic bond
An ionic bond forms when one atom transfers electrons to another atom, creating oppositely charged ions that attract each other.
Isotope
An isotope is an atom of an element that has the same number of protons but a different number of neutrons.
Kinetic theory of matter
The kinetic theory of matter states that all matter is made of tiny particles that are always in motion.
Mechanical energy
Mechanical energy is the sum of an object's kinetic energy and potential energy.
Momentum
Momentum is the quantity of motion an object has, calculated by multiplying its mass times its velocity (p = mv).
Neutron
A neutron is a particle in the nucleus of an atom that has no electric charge.
Newton's first law
Newton's first law states that an object at rest stays at rest, and an object in motion stays in motion at the same speed and direction, unless acted upon by an unbalanced force.
Newton's second law
Newton's second law states that the acceleration of an object depends on the net force acting on it and its mass (F = ma).
Newton's third law
Newton's third law states that for every action force, there is an equal and opposite reaction force.
Ohm's law
Ohm's law states that voltage equals current times resistance (V = IR).
Parallel circuit
A parallel circuit has components connected on separate branches, so electricity can follow multiple paths.
Periodic table
The periodic table is a chart that organizes all known elements by their atomic number and chemical properties.
Power
Power is the rate at which work is done or energy is transferred, measured in watts.
Proton
A proton is a positively charged particle found in the nucleus of an atom.
Radiation
Radiation is the transfer of energy through electromagnetic waves that can travel through empty space.
Resistance
Resistance is a material's opposition to the flow of electric current, measured in ohms.
Series circuit
A series circuit has all components connected in one single loop, so electricity follows only one path.
Sublimation
Sublimation is when a solid changes directly into a gas without first becoming a liquid.
Thermal expansion
Thermal expansion is the tendency of matter to increase in volume when heated as its particles move faster and spread apart.
Voltage
Voltage is the electrical pressure that pushes electric charges through a circuit, measured in volts.
Wave properties
Wave properties include amplitude (height), wavelength (distance between peaks), frequency (waves per second), and speed.
Work
In science, work is done when a force moves an object over a distance, calculated as W = F x d.