| A | B |
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| Chemical change | Chemical changes occur at the atomic level, which means we can’t actually see them happening. There are three main signs to look out for when trying to identify a chemical change: 1) a new substance being made, 2) a change that can’t be undone, 3) heat is released or absorbed. |
| Physical change | A change from one state (solid or liquid or gas) to another or a change in a property of a property of a material without a change in chemical composition (ex: ice melting, water freezing, breaking a rock into smaller pieces). It does not change into another substance. |
| Properties of materials | The traits of an object that can be readily seen such as texture, size, color, weight, and state (solid, liquid, gas). |
| States of matter | Three traditional states of matter are solids (fixed shape and volume), liquids (fixed volume and shaped by the container), and gases (filling the container, no fixed volume). |
| Changes in states of matter because of temperature | Molecules within matter move faster and move farther apart as energy (heat) is increased. They will move from solid to liquid to gas. |
| Conduction | Occurs when heat energy flows from one molecule to another as they collide. Molecules transfer energy by touching. |
| Conductor | A material through which heat passes easily. Metals like copper, aluminum, and steel are all good conductors. |
| Kinetic energy | Energy in motion. |
| Potential energy | Stored energy. |
| Heat | The flow of thermal energy from one place to another. |
| Convection | The transfer of energy when a large mass of a liquid or gas (a fluid) moves from one place to another. Fluid or gas particles move from one location to another, carrying energy with them. |
| Electromagnetic waves | Invisible waves of energy being transmitted through space (ex: energy from the sun reaching Earth). |
| Insulator | A material that delays or inhibits movement of heat. Wood and plastic are good insulators. |
| Radiation | The transfer of energy in the form of waves without contact of particles transferring energy. |
| Thermal energy | Energy found within matter. |
