Physical/Chemical Changes

Admit Slip

Identify the following as elements or compounds:

C

C6H12O6

H2

CO2

Today’s Objectives:

Students will be able to: Define and compare elements, compounds, and

pure substances Describe chemical changes, physical changes,

and conservation of matter

Agenda

Discussion Homework Check/Review Notes Questions Exit Slip

Notes

During a physical change, some properties of a material change but the composition does not change.

Physical changes include boiling, freezing, melting, condensing, breaking, filtering, distilling, cutting, separating, and mixing.

They may change the physical form of matter but do not change its composition.

Notes

During a chemical change, the composition of the matter always changes. A chemical change is also known as a chemical reaction.

Words that indicate chemical changes are “reacts, burn, rot, rust, decompose, ferment, explode, and corrode”

Notes

In a chemical reaction, the substance at the beginning is called a reactant and the end result is a product.

H2O H2 + O2

Reactants Products

Notes

Possible clues to a chemical change/reaction include energy transfer, a color change, the production of a gas, or the forming of a precipitate.

A precipitate is a solid that forms and settles out of a liquid mixture during a reaction.

Notes

During a chemical reaction or physical change, the mass of the products always equals the mass of the reactants.

This is the Law of Conservation of Mass. Mass can not be created or destroyed.

Question 1

Identify the following as mixtures, elements or compounds:

Green ink

O2

Fruit punch

Salt, NaCl

Question 2

Identify the following as mixtures, elements or compounds:

Copper

Ice

Sugar water

CaS

Question 3

Identify the following as mixtures, elements or compounds:

Sugar, C6H12O6

soda

CH4

Fluorine

Question 4

Classify each of the following as a physical or chemical change: Explain why.

A copper wire is bent

Charcoal burns in a grill

Bread dough rises when yeast is added

Sugar dissolves in water

Question 5

In your own words, what is the difference between an element and a compound?

Question 6

In your own words, what is the difference between a compound and an mixture?

Question 7

When ammonium nitrate NH4NO3 explodes, the products are nitrogen, oxygen, and water. When 40 g of ammonium nitrate explode, 14 g of nitrogen and 8 g of oxygen form.

How many grams of water form?

Exit Slip/Homework

Exit Slip: Show me your work from today.