Physical and Chemical Change Physical Science Physical and Chemical Change

physical change A ___________ ___________ alters the form of an object without changing what type of matter it is. Changes in size,shape,or color are examples of a physical changes.

solid, liquid 2. Change of state is an example of a physical change. A substance can change from a __________ to a __________. The substance does not change its chemical identity in this process. An ice cube melting is an example of a physical change because frozen or liquid, it is still water.

reversed 3. Some physical changes can easily be ____________. However, some are more difficult to reverse than others. Ice melting can be reversed by cooling it. Other mixtures need more advanced methods to reverse their changes: distillation, evaporation.

chemical changes,chemical reaction 4.__________ ___________ occur when atoms link together in new ways to create substances different from the original substances. This is also known as a ___________ _________.

bubbles 5.If you combine baking soda with vinegar,a chemical change occurs because ___________ form. The bubbles are a new substance. Also, a new white solid is left behind.

chemical equations 6. Chemists write equations for chemical changes similiar to math equations.They call them ___________ _____________.

reactants, products Chemicals on the left side of a chemical equation are called ____________________; chemicals on the right side are called ____________________.

mass,conservation of matter 8.In every chemical reaction, the total mass of the reactants always equals the total ___________ of the products. This fact is known as the Law of ________________ ______ ________.

new,see,hear,smell 9. Chemical changes produce _____ substances. These substances have different properties than the previous ones. Often you _____,______, or _________ the formation of new substances as a chemical change occurs.

change,color 10.A ___________ in ___________ is one sign of a chemical change. When bleach whitens a cloth, it does so by chemically changing the dyes on the cloth or the cloth itself.

tarnish 11.When corrosion of metal causes a color change, it is called ____________.

bubbles 12.When you place an antacid tablet in water, a chemical reaction occurs and _____________ form. The appearance of bubbles is another sign that a chemical change has occurred.

precipitate 13. Chemical changes can produce more than just gases a _______________ is a solid formed from the chemical reaction of some solutions. An example of precipitate is soap scum.

light,heat 14. Some chemical changes involve the release of _________ and ____________. A burning candle, for instance, produces a hot flame.

energy 15. Chemical reactions are taking place all the time. They allow living things to carry out their life functions. For example, when plants use _______ from the Sun to help them create simple sugars. This process is called photosynthesis.

hydrogen,oxygen 16. Machines can also use the energy from chemical reations. In a space shuttle, ____________ and ____________ molecules combine to push the shuttle upward.

compounds 17. Chemical reactions are the only way to form _____________. Some compounds such as fossil fuels, are formed in nature.