7th grade unit 10: chemical reactions and compounds lesson 1: chemical properties and changes...

7th Grade

Unit 10: Chemical Reactions and Compounds

Lesson 1: Chemical Properties and

Changes

Vocabulary of Instruction:

1. Chemical Change• The atoms of a

substance are rearranged into new substances with different chemical composition.

• Some evidence of a chemical change include: – color change– odor change – bubbling– fizzing (production of

gas)– production of light or

heat and the – formation of a solid

(precipitate).

2. Chemical Property• Describes a

substance’s ability to lose its original identity and change into one or more new substances.

3. Chemical Reaction• Describes the

interaction or combination between two or more substances that produces new substances, which characteristics are different from the original substances.

4. Combustion• A chemical

reaction in which a substance (fuel, paper, wood, plastic, etc.) reacts with oxygen to give off heat and light. The act or process of burning, ignition, or incineration.

5. Corrosion• The process of the

destruction, deterioration, or decomposition of a metal when it is exposed to air and water.

6. Oxidation• A chemical

reaction with oxygen that removes electrons from an element or compound.

7. Physical Change• The

transformation of the external appearance of a substance that does not convert it into a new substance.

8. Physical Property• The external

appearance or characteristic of a substance that can be observed.

Odor

Color

hardnessStructure

Solubility

melting point

9. Tarnish• Layer of corrosion that is formed on the

surface of metals or alloys due to corrosion or oxidation.

10. Reactant• The substances or compounds that you start

with in a chemical equation (left side).

REACTANT

11. Product• The substances or compounds that you have at

the end of a chemical equation (right side).

PRODUCT

12. Element• A substance

that can not be broken down into any other substances by chemical of physical means (carbon, hydrogen, oxygen, nitrogen, etc.).

13. Compound• A substance

made of two or more elements that are chemically bound together in a set ratio.

Examples:– carbon dioxide– water

14. Chemical Equation• A short, simple way to describe a chemical

reaction using symbols and formulas instead of words, such as photosynthesis and respiration:

6CO2 + 6H2O + Sunlight 6O2 + C6H12O6 + Heat

Example Equation: