Unit 1 Matter: Solid, Liquid, and Gas
I am learning about states of matter.
I can describe similarities and differences between solid, liquid and gas.
I can explain and diagram the phase changes of matter: condense, evaporate, freeze, and melt.
I am learning about particle motion (kinetic energy).
I can identify the relationship between particle motion (kinetic energy) and state of matter.
I can draw a model to demonstrate how thermal energy affects particle motion.
Matter in Motion
Standard 6-PS1-4: Develop and use a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed.
Matter is anything that has mass and takes up space. All matter is made of tiny particles called atoms and molecules. These particles are always in motion, and this is called particle motion. The speed of this motion is related to kinetic energy—the energy of movement. When particles move faster, they have more kinetic energy.
Thermal energy is the total energy of all the moving particles in a system. When you add thermal energy to a substance, the temperature increases, which means the particles move faster. When you remove thermal energy, the temperature drops, and the particles slow down.
A pure substance is a type of matter made of only one kind of particle—either one type of atom or one type of molecule. For example, water is a pure substance. A pure substance can exist in three different phases: solid, liquid, and gas. Each phase has different particle motion. In a solid, particles vibrate in place. In a liquid, particles slide past each other. In a gas, particles move freely and quickly. Some gases are made of inert atoms, like helium, which don't easily react with other substances.
When thermal energy is added or removed, a phase change can occur. When you add heat to ice, it will melt into liquid water. If you keep adding heat, the water will evaporate and turn into a vapor or gas. You can also boil water to make it change to gas more quickly by increasing pressure and temperature.
When you remove thermal energy, the opposite happens. Water vapor will condense back into liquid, and liquid water will freeze into solid ice.
Understanding how particles behave helps us predict and explain phase changes in matter.
