Physical and Chemical Changes Ms. W. Smith-McKenzie Warm Up List as many physical and chemical properties of the Statue of Liberty as you can in two minutes. What are Physical and Chemical Changes? Physical and chemical changes occur when the matter of a substance changes in some type or form. • These changes can be identified based on the physical or chemical property being observed. • Mass is not gained or lost during physical and chemical changes. What are Physical and Chemical Changes? • Check For Understanding • CFU: Give an example of a physical property and a chemical property. • Answer: • Physical properties include color, texture, ductility, density, solubility, state of matter • Chemical properties include flammability, reactivity, ability to rust. Physical Changes • Physical changes occur when there is a change in the form of a substances; however the chemical composition of the substance remains the same. • Physical changes can be determined by observing the physical properties of a substances. Physical Changes • Examples of physical changes include crumbling paper, chopping wood, and ice melting. Physical Changes • CFU: John chops a 25 kg log into pieces. He gathers all of the pieces and puts them on the scale. How much do the pieces weigh? • A. More than 25 kg • B. Less than 25 kg • C. 25 kg • Answer: C Chemical Changes • Chemical changes occur when there is a change in the chemical composition of the substance. This can happen when two or more substances combine and a new substance is formed with properties and structures differing from the original substances. • Chemical changes can be determined by observing the chemical properties of a substances. Chemical Changes • Examples of chemical changes include burning, fruit ripening, and reactivity to a substance. Chemical Changes • CFU: How do we know that burning wood is a chemical change? • A. After the wood is burnt, the ending substance is still the same (wood). • B. After the wood is burnt, a new substance is produced (ash, soot) with new properties. • C. The wood looks the same. • Answer: B Name that change: What type of change is taking place in the following scenarios? Physical Change Chemical Change Physical Change Physical Change Chemical Change Chemical Change Chemical Change Note: • All images included in this PowerPoint are unlicensed and are part of the public domain.