Physical and Chemical Changes
What is this about exactly????
This section covers everything about physical and chemical changes! We also learn how temperature can influence chemical changes!
Vocabualary you NEED to know!
Physical change: a change from one state (solid,liquid, or gas) to another without a change in chemical composition
Chemical change: any process determined by the atomic and molecular composition and structure of the substances involved (caused by a chemical reaction)
Big Idea!!!
Physical and Chemical changes happen all the time! It even happens when you least expect it!
Physical changes are the easiest in my opinion! The object is the same object but it can be in a different state! Look at the picture below to see some examples.
Now Chemical Changes are totally different and occur when one item gains totally new properties by a chemical reaction. Once the item is used in a chemical reaction it cannot return to its original state.
A good example is if you bake a cake. You decide to use flour and sugar and mix that into the batter and bake it. But once you bake the cake, you can not get those individual ingredients back!
Example of Changes
How does temperature influence chemical changes?
Temperature influences chemical change by increasing the reaction rates (which is the rate at which chemical change will occur). The hotter the temperature is, the faster the gas particles will move (look back to 7th grade when we learned about solids,liquids,and gases) and how fast or slow each state of matter moves.
When the particles move faster they gain more energy which allows the particles to collide into each other at a greater percentage. When the particles finally collide into each other chemical change occurs!
