Starter: Evidence of Chemical Reactions 10/22/15 Practice: Notes over Chemical Evidences 10/22/15 Evidence of Chemical Reactions Application Evidence of Chemical Change ppt activity Connection: Physical vs. Chemical Changes Practice Exit: Write 3-4 sentences explaining what you have learned about chemical changes today. Identify the parts of a chemical equation EQ: How can comparing and contrasting help me to understand how matter physically or chemically changes?
October 22, 2015 AGENDA 8.5 F. I will be able to recognize whether a chemical equation containing coefficients is balanced or not and how that relates to the law of conservation of mass by reading, and writing while completing an activity. 1.Starter 2.Notes 3.Activity 4.Ws 5.Exit
DateLecture/ Activity/ Lab Page Table of Contents 9/25 Test Review /29 Periodic Puzzles /30 Bohr Model Challenge /1 Wheres Al? /2 Element Wanted Poster /6 Molecules, Compounds, and Elements /07 Build a Molecule Activity /8 Counting Atoms /09 Counting Atoms with Coefficients /10 Chemical Formula Writing /13 Writing Chemical Formulas /14 Chemical Equations and the Conservation of Mass /15 Balancing Act /16 A Beady Balance /19 See Saw Poster /20 Law of Conservation of Mass Lab /22 Evidence of Chemical Reactions 71-72
Starter: Label the parts of the equation Coefficient Chemical Formula Element yields subscript
Physical vs. Chemical Changes Notes
Matter undergoes changes all of the time.
There are two types of changes: chemical physical &
Physical changes:
Physical changes occur when the appearance of a substance changes…
chemically …but chemically the substance is the same.
The individual molecules do not change.
Examples of physical changes are, melting, freezing,
or changing size or shape.
A physical change also occurs when substances are…
mixed and something dissolves…like making salt water or Kool- aid.
The water, salt and sugar still keep their original properties and the substances can be separated again.
Chemical Changes
A chemical change occurs when the atoms making up matter rearrange..
to form a new substance with new properties.
This usually occurs during a chemical reaction.
Evidence of a chemical change:
Production of a gas.
bubbles fizzing foaming smoke odor
color change *not all color changes are chemical!
A different color appears
*not all color changes are chemical!
Formation of a precipitate
cloudiness foggy solid at bottom of container
Change in heat or light energy
Sparks explosion glowing
temperature increases or decreases
These are only clues…
…a chemical change has not actually taken place unless matter has changed into a new substance.
Some common examples of chemical changes include…
Rusting…
Tarnishing…
Burning…
Cooking…
Digesting…
If you have the chemical equation, you can tell if a chemical change has taken place by…
Looking to see if the products in the equation are….
different from the reactants.
Evidence of Chemical Change TEKS 6.5D identify the formation of a new substance by using the evidence of a possible chemical change such as production of a gas, change in temperature, production of a precipitate, or color change. TEKS 8.5E investigate how evidence of chemical reactions indicate that new substances with different properties are formed.
acid rain on a statue
digesting a hamburger
photosynthesis
a nail rusting
tarnish on pennies
Starter: Evidence of Chemical Reactions 10/22/15 Practice: Notes over Chemical Evidences 10/22/15 Evidence of Chemical Reactions Application Evidence of Chemical Change ppt activity Connection: Physical vs. Chemical Changes Practice Exit: Write 3-4 sentences explaining what you have learned about chemical changes today. Identify the parts of a chemical equation EQ: How can comparing and contrasting help me to understand how matter physically or chemically changes?