MS - PS1.A(B) - Chemical Properties and Interactions - FINAL (WND 1-8-2014)

DCI: PS1.A (B) Each pure substance has characteristic physical and chemical properties (for any bulk quantity under given conditions) that can be used to identify it.

PE: MS-PS1 -2 Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.

PE: MS1 - PS1-3 Gather and make sense of information to describe that synthetic materials come from natural resources and impact society.

 [Clarification Statement: Examples of reactions could include burning sugar or steel wool, fat reacting with sodium hydroxide, and mixing zinc with hydrogen chloride.] [Assessment boundary: Assessment is limited to analysis of the following properties: density, melting point, boiling point, solubility, flammability, and odor.]

[Clarification Statement: Emphasis is on natural resources that undergo a chemical process to form the synthetic material. Examples of new materials could include new medicine, foods, and alternative fuels.] [Assessment Boundary: Assessment is limited to qualitative information.]

The ideas we see in this standard are: 

- Each pure substance can be identified by examining its physical and chemical properties

- The properties of substances will change if it undergoes a chemical reaction 

- It can be determined if a substance has gone through a chemical reaction if its properties have changed 

- natural materials can be changed chemically to form synthetic materials which impact society

It seems that this standard is laying the foundation for later standards which have the expectation that students understand what happens during a chemical reaction.  This, though, is much simpler.  Students should know that different substances can be identified by their properties. The emphasis is on the fact that the properties of materials will change if the material is changed chemically. Because this is a physical science standard, and because students were exposed to the term chemical reaction in earlier grades, it is probably ok to use that terminology.  

To address the first PE, we will simply provide data about the properties of a given substance or set of substances before and after an interaction and ask students to evaluate if a chemical reaction took place. 

As far as the second PE, we can provide background information on some of these synthetic materials, and ask them to come to the general conclusion that natural resources were chemically altered. 

Possible Question Starters

"A student finds the mass and volume of four mystery liquids.  The data is provided here. 

Liquid	Mass (g)	Volume (mL)
1	5	5
2	6	2
3	2	1
4	8	2

The student knows that the density of water is 1 g/mL.  Which of the mystery liquids can be identified as water?"

"Information on three sources of alternative fuel is provided. 

Alternative Fuel	Source	Amount of time to make	Processes involved
Ethanol	Corn Sugar cane Potato	3-5 days	Grinding Distillery
Hydrogen	Water Methane Organic Matter	1-3 hours	Steaming Electrolysis Fermentation
Biodiesel	Cooking Oil Animal Fats Restaurant Grease	6-8 hours	Transesterification

Based on the information, which of the following statements about alternative fuel sources is correct?"

correct answer - alternative fuels are made from natural materials

incorrect answer - alternative fuels require great amounts of time to manufacture