When a liquid is cooled even more, it freezes and becomes a soli called freezing or solidification. These changes are called changes in state, and they happen beca temperature. Understanding this helps us explain everyday things like me or fog forming on a cold window. Assessment: Explain the following 1. What happens to the particles of a solid when it is heated? 2. Why temperature is important in changing the state of matter? 3. What is the difference between melting and boiling? 4. Give one example of change from gas to liquid in everyday life. 5. What state change occurs when water turns into ice?
Answer (1)
1. What happens to the particles of a solid when it is heated? Let's assume the solid in surrounded by air (or vacuum in space). As heat is added to particles of a solid, they start vibrating. As enough heat is added, individual particles will gain enough energy to "evaporate" into the surrounding air or vacuum. This event is termed vaporization or boiling.2. Why temperature is important in changing the state of matter? All matter has a set of physical properties that describe the state (solid, liquid, or gas) of that matter under specified conditions of temperature and pressure. For a given pressure, one can predict the state of matter at a specific temperature. The boiling point is the temperature at which that matter will begin to vaporize (at a specific pressure). This is important in the design of vessels for a chemical reaction, for example.3. What is the difference between melting and boiling? Melting refers to matter going from a solid to a liquid. Boiling means it goes from a liquid to a gas. Some materials can go from solids to gases without going through a liquid phase, a process called sublimation. The process of going from gas directly to solid is called deposition.4. Give one example of change from gas to liquid in everyday life. Rain occurs when water molecules in the gas phase coalesce into water droplets that, once large enough, fall to Earth in an event we call rain.5. What state change occurs when water turns into ice?This is called freezing. A liquid transforms into a solid.
