Properties+of+Matter+Notes

__**POM-8 (Changing Matter and Mass)**__ Our investigative question was **"How does changing phases change the mass of a substance?"**

In this activity students found that changing from one state of matter to another __did not change__ the mass of the substance. In science we describe this as the **Law of Conservation of Mass** which states that in a physical or chemical change, matter cannot be created or destroyed (or in otherwords, what mass/matter you have before the change is the same as what you will have after the change). In a process like boiling, matter (atoms) can sometime escape and move to a place we can't measure it (like into the air/atmosphere) but the matter is NOT LOST.

__**POM-7 (Just a Phase)**__ Our investigative question was still **"What effect does heating (thermal energy) have on a solid substance?"**

This activity had students focus specifically on the physical changes of matter when heated. Students found that matter chnages temperature in a pattern that we saw in a heating/cooling graph (of our data). From this graph we could identify the **melting/freezing point** (the temperature a substance changes between solid and liquid) and the **boiling/condensing point** __**(**__the temperature a substance changes between a liquid and a gas). These points are indicated by flat or horizontal sections on the graph which show very little or slow change in temperature.

__**POM-6 (Applying Heat)**__ (This a PowerPoint presentation. Try opening it with PowerPoint.) Our investigative question was **"What effect does heating (thermal energy) have on a solid substance?"**

Students found that we can classify our changes from heating in two categories. **Physical changes** are when the substance is the same but simply changes phase (solid, liquid or gas). We will learn more about physical changes in POM-7. **Chemical (changes) reactions** produce new compound(s) which have new and different properties.

Chemical reactions can be broken down into two parts - the **reactants** (the substances we start with) and **reactants** (the substances we finish with). Some reactions are reversible (like Copper Sulfate and water from POM-6), while others are permanent (like Alka Selzer and water from POM-0).