Agenda: Friday, March 22nd

1) Warm-up – 10 min2) Coefficients review – 20 min3) Chemical Change Review – 20 min4) Open-Note Quiz – 30 min

   

Answer the 3 CST questions the same way we did on Tuesday: Write down your answer, key words, and reason you chose the answer.

   

Sometimes a change seems irreversible when it is.

For example, when dry ice sublimates, can we reverse it?

   

Yes we can!Dry ice undergoes deposition at -78 degrees

Celsius. If we decrease the temperature below that, Carbon Dioxide gas will re-form into dry ice

   

If we recycle a can and it gets crushed in order to make something else.. is it a chemical change because it changed into something else?

   

No! Because even though the can gets changed into something else, the aluminum molecules in

the can do not get changed.

   

What is an example of a chemical change to a table?

   

In a chemical change the molecules in the table would react and form other molecules, such as carbon dioxide gas and ash (made of carbon).

   

Chemical and Physical Changes

Definition of a Chemical change:1) Substance changes its identity2) Irreversible3) New molecules are formed

Definition of a Physical change:1) Substance changes appearance, not identity2) Reversible3) Same molecules after change as before4) All phase transitions

Draw 2 examples of each type of change – 20 pts

   

Mini poster

With a sheet of paper, create a mini foldable for a chemical and physical change. Mr. Lee will

demonstrate.

   

Coefficients and Chemical Changes

Read pages

and answer questions

   

Quiz: Open Notes