10.4 Chemical Properties and Changes 10/19/2015 Add the new notes to your table of contents, and then turn to the next clean page and set up your title and date

Lesson 4-1 A chemical property is a characteristic of matter that can be observed as it changes to a different type of matter.chemical property Chemical Properties Add “chemical property" to our index before moving forward

Lesson 4-2 Ability to burn (flammability) Ability to rust Ability to tarnish What are some chemical properties of matter? Ability to rot Ability to spoil Acidity

Lesson 4-3 A chemical change is a change in matter in which the substances that make up the matter change into other substances with new physical and chemical properties.chemical change The substances that undergo a chemical change no longer have the same properties because they no longer have the same identity. Chemical Changes Add “chemical change" to our index before moving forward

Chemical properties describe the abilities of matter to change –Examples: ability to burn, ability to rot, ability to spoil Chemical changes are actual events that change matter –Examples: burning, rotting, spoiling What makes a chemical change different from a chemical property?

Lesson 4-3 Chemical Changes (cont.) What is the difference between a physical change and a chemical change?

Lesson 4-3 Chemical Changes (cont.) What is the difference between a physical change and a chemical change? A physical change can be observed without changing the matter's identity, a chemical change can only be observed as the matter becomes something different

Lesson 4-4 How do you know when a chemical change occurs? –Signs of chemical changes include: the formation of bubbles, a change in odor, a change in color, or a change in energy Signs of Chemical Change

Lesson 4-4 These signs do not always mean a chemical change occurred. The only proof of chemical change is the formation of a new substance. Signs of Chemical Change

Lesson 4-5 Recall that particles in matter are in constant motion. As the particles move, they collide. If the particles collide with enough force, the bonded atoms that make up the particles can break apart. Then the atoms rearrange and bond with other atoms. When atoms bond together in new combinations, new substances form. This process is called a chemical change or a chemical reaction. Chemical Reactions

Lesson 4-5 A useful way to understand what happens during a chemical reaction is to write a chemical equation. A chemical equation shows the chemical formula of each substance in the reaction. Chemical Reactions

Lesson 4-5 In a chemical equation, the number of atoms of each element before a reaction must equal the number of atoms of each element after the reaction. This is called a balanced chemical equation, and it illustrates the conservation of mass. When balancing an equation, you cannot change the chemical formula of any reactants or products. Chemical Reactions & Conservation of Mass

Lesson 4-5

Let’s practice balancing some simple equations H 2 + O 2 -> H 2 O

Let’s practice balancing some simple equations KClO 3 -> KCl + O 2

Let’s practice balancing some simple equations Ag + S 4 -> AgS 2

Lesson 4 - VS A chemical property is observed only as a material undergoes chemical change and changes identity. Signs of possible chemical change include bubbles, energy change, and change in odor or color. Chemical equations show the reactants and products of a chemical reaction and that mass is conserved.

Lesson 4 – LR1 A.chemical change B.chemical equation C.chemical formula D.physical change Which term refers to a change in matter in which the substances that make up the matter change into other substances with new physical and chemical properties?

Lesson 4 – LR2 A.same number of atoms B.same number of compounds C.same number of molecules D.same number of reactants What must a balanced chemical equation have on both sides of the equation?

Lesson 4 – LR3 A.Paper is shredded. B.Liquid wax turns solid. C.A raw egg is broken. D.A wood log is burning. Which is a chemical change?

Lesson 4 - Now 7.When wood burns, new materials form. 8.Temperature can affect the rate at which chemical changes occur. Do you agree or disagree?