Chapter 3

1. Section 3

1.1. every chemical reaction involves a change in energy some reaction absorbs energy and other realses it

1.2. The rate of a chemical reaction can be controlled by such factors ad concentration surface area temperature and use of a catalyst or inhibtor

2. Section 1

2.1. Matter may be in the form of elements compounds or mixtures.

2.2. chemical changes result in the formation of new substances physical changes do not

2.3. color changes prosecution of a gas or a precipitate a change in temperature or a change in the properties of a substances are all clues that a chemical reaction has taken place

2.4. Chemical reaction occurs when chemical bonds are formed or broken

3. Section 1 vocab

3.1. Chemistry:The study of the properties of matter and how matter changes

3.2. Element:A substance that can not be broken down into any other substances by chemical of physical means.

3.3. Compound: Is a substance made of two or more element chemically combined in a specific ratio, or porportion

3.4. Mixture: Is made from two or more pure substances elements, compounds, or both that are the same place but not combined as a new material.

3.5. Solution: Is a well mixed mixture

3.6. Physical change:A change that alters the form or appearance or a material but does not make thhe materiel into another substance

3.7. Chemical change:A change in matter that produces a new substance.

3.8. Chemical reaction:The process in which substances undergo chemical changes that result in the formation of new substances

3.9. Precipitate:A solid that forms form a solution during a chemical reaction

3.10. Atom:the smallest particle or an element

3.11. Molecule:the combination of two or more atoms

3.12. Chemical bond:The force that holds atoms together

4. Section 2 vocabulary

4.1. Chemical equation:A short easy way to show a chemical reaction using symbols instead of words

4.2. symbols:A one or two letters set of charters that is used to identify elements

4.3. Chemical formula:A combination of symbols that represent the element in a compunds

4.4. Subscripts: A number in a formula written lower and smaller than the symbol to indicate the number of atoms of an element in a molecule.

4.5. reactants:A substances that enters into chemical

4.6. Products:a substances formed as a result of a chemical reaction

4.7. Conservation of mass:The principle starting that matter is not created or destoryed during a chemical reaction

4.8. Coefficient:A number informant of a chemical formula in a equation that indicates how many molecules or atoms

4.9. Synthesis:A chemical reaction in which two or more simple substances combine to form a new more complex substance

4.10. Decomposition:A chemical reaction that brakes down compound into simpler products

4.11. Replacement reaction:A reaction in which one elements repales another in a compund or when two elements in diffrent compunds tradde places

5. Section 3 Vocabulary

5.1. Exothermic reaction:A reaction tht relases energy in the form of heat

5.2. Endothermic reaction:A reaction that absorbs energy in the form of ehat

5.3. Activation energy:The minimum amount of energy that has to be added to get a chemical reaction started

5.4. Concentration:The amount of one material in a certain volume of another material

5.5. Catalyst:A material that increases that rate of a chemical reaction by lowering the activation energy

5.6. enzyme:A biological catalyst that lowers the activation energy of reaction in cells

5.7. inhibitor:A material that decresses the rate of a reaction

6. Section 2

6.1. A chemical equation uses symbols to show the reactions and products of a chemical reaction

6.2. Matter is neither created nor destroyed during a chemical reaction

6.3. Chemical reaction may be classified by the types of changes in reactants and products

7. Section 4

7.1. The fire triangle shows the three things necessary to start a fire and keep it burning fuel air and heat

7.2. Water stops combustion by keeping the fuel from coming in contact with oxygen also evaporation of water uses a great deal of what and cools the fire

8. Section 4 vocab

8.1. Combustion: A rapid reaction between oxygen and fuel that rustults in fire

8.1.1. fuel:A material that relases energy when it burns

9. Video: Water,and salt are forms of compounds

9.1. We have millions of substances on our planet because the atoms are able to combine to form new substances called compounds.

9.2. Chemical Formulas: NaCl is a chemical formula of table salt

9.3. Neon is rarely found in a compound.

9.4. Noble gases have 8 valance electrons while the other elements have 1-7 valance electrons.