REVERSIBLE AND IRREVERSIBLE CHANGES
Dissolving sugar in water is a(n) ___________________ change
reversible
You mix two things together and it fizzes and bubbles. Has a chemical reaction happened? How can you tell?
Yes. It formed a gas.
If something has a pH of 2, it is a(n) _____________.
acid
On the surface of the water, the water particles are stuck together, making the top of the water strong.
Baking cookies is an example of a(n) __________________ change
irreversible
How can you test if something is carbon dioxide or if it's just air.
Lighting a stick and seeing if it will stay lit when exposed to it.
If something has a pH of 10 it is a(n) _____________.
Base
Melting a popsicle is an example of a(n) _______________ change.
reversible
What are two signs that let us know that fire is a chemical reaction.
Change in temperature
Change in odour
Change in colour
Produces a gas
Produces light
When pouring cabbage juice into an acid, what colour will it turn?
Red
How can water striders walk on water?
Define what a reversible change is and give an example.
A change that can be undone
Ex: melting, freezing, evaporation, condensation, dissolving, blowing up a balloon, molding clay.....
What is the difference between a physical and chemical change?
A physical change is only changing how something looks
A chemical change is changing the chemical make up of something, and making something new that wasn't there before.
When pouring cabbage juice into a base, what colour will it turn?
Blue/Green
Describe cohesion
Water molecules are attracted to each other and stick together.
Define what an irreversible change is and give an example
A change that can NOT be undone
ex: baking, cooking, burning, breaking, elephant toothpaste.......
What are the six ways to know that a chemical reaction has happened?
Formation of solid
Formation of gas
Produces light
Change in temperature
Change in colour
Change in odour (smell)
If you pour cabbage juice into a liquid and it stays purple, the liquid is _____________.
Put the following in order from most cohesion to least cohesion
oil, rubbing alcohol, water
water, oil, rubbing alcohol