6th Grade Science / Lesson 9 - Change Identity
What will we be learning today?
How Do Things Change Identity?
What is steel wool? What do people use it for? Steel wool is a fine wire of steel bundled up like yarn. It is used to scour pots and pans. Steel wool is made mainly of iron. If you soak steel wool in strong vinegar, blot it fairly dry, and let it stand in moist air for an hour or so, something interesting happens. A brown powder forms that is loosely attached to the steel wool. The powder forms because the iron in the steel wool has undergone a change. It has combined with oxygen from the air to form a new substance called rust. The chemical name of rust is iron oxide. The rust is a reddish powder that flakes off the metal. Over time all the iron will change to rust. This kind of change is called a chemical change. In any chemical change, new substances are produced with physical properties different from the starting substances. Chemical changes often show one or more key signs. A color change may occur, heat and light may be given off, a gas may be produced, or a powdery solid may form. Steel wool changes to rust when put in vinegar.
A powder forms. This is a sign of a chemical change. Gas forming is a sign of a chemical change.
Heat and light are signs of a chemical change. Let's Review What We Learned Today!