Physical and Chemical Changes
Shelby Brown
8/28/10
Physical and chemical changes lab essay
Changes in matter occur every day. There are two types of ways matter can be altered; physically and chemically. Physical changes do not change the composition of the matter while chemical changes occur when one or more substances turn into a completely new substance. Physical changes can be seen through an altering of the substances physical property. A substances physical property is observed and measured without changing the composition of the subject. Descriptive words that would help to identify a substance’s physical property include hard, soft, brittle, flexible, heavy, and light just to name a few. When an object goes through a physical change it remains the same substance. For example if you cut a sheet of paper it would still be paper however, it would be a different shape. Physical changes called phase changes occur when a substance changes from one form of matter to another. An example of this would be the melting of ice and boiling of water. When an ice cube melts it turns into water and when the water is boiled it turns into steam or vapor. As one can see an ice cube, water, and steam have extremely different physical properties. Ice cubes are solids, water is a liquid, and steam is a gas. In this physical change the substance has undergone two phase changes from solid to liquid and from liquid to gas. These are extreme physical changes because the composition has not changed meaning that throughout the changes the substance was always H2O it is in no way a chemical change. Chemical changes also known as chemical reactions occur when one or more substances combine to make a completely new substance. Similarly to physical changes a substances chance of undergoing a chemical change is dependant upon its chemical properties. A substance’s chemical properties are largely based off of how easy or difficult it is for that substance to combine with another
8/28/10
Physical and chemical changes lab essay
Changes in matter occur every day. There are two types of ways matter can be altered; physically and chemically. Physical changes do not change the composition of the matter while chemical changes occur when one or more substances turn into a completely new substance. Physical changes can be seen through an altering of the substances physical property. A substances physical property is observed and measured without changing the composition of the subject. Descriptive words that would help to identify a substance’s physical property include hard, soft, brittle, flexible, heavy, and light just to name a few. When an object goes through a physical change it remains the same substance. For example if you cut a sheet of paper it would still be paper however, it would be a different shape. Physical changes called phase changes occur when a substance changes from one form of matter to another. An example of this would be the melting of ice and boiling of water. When an ice cube melts it turns into water and when the water is boiled it turns into steam or vapor. As one can see an ice cube, water, and steam have extremely different physical properties. Ice cubes are solids, water is a liquid, and steam is a gas. In this physical change the substance has undergone two phase changes from solid to liquid and from liquid to gas. These are extreme physical changes because the composition has not changed meaning that throughout the changes the substance was always H2O it is in no way a chemical change. Chemical changes also known as chemical reactions occur when one or more substances combine to make a completely new substance. Similarly to physical changes a substances chance of undergoing a chemical change is dependant upon its chemical properties. A substance’s chemical properties are largely based off of how easy or difficult it is for that substance to combine with another