April 17, 2024 Classwork

Physical & Chemical Changes
BENCHMARK:
SC.8.P.9.2 Differentiate between physical
changes and chemical changes. (Also assesses
SC.8.P.9.1 and SC.8.P.9.3.)

ESSENTIAL QUESTION:
How can you use evidence to determine if a
change is physical or chemical?

Multilingual Glossaries for Middle School Science

Please click on the link below, use your dictionary or the lesson
glossary to look for the meaning of words as you go through the

lesson

Lesson Glossary - Key Vocabulary Terms

Lesson Glossary - Key Vocabulary Terms

Lesson Glossary - Key Vocabulary Terms

Multiple Choice

Bellringer

Michael decides to bake bread one morning. He measures ingredients, mixes them together to make a dough, and cooks the dough in an oven. As the dough cooks, Michael observes the bread rising. Which of the following is evidence of the chemical change in Michael’s break-making process?

•  Sugar dissolving in the liquid batter.

• The bread rising as carbon dioxide is released.

• Water in the dough being released as water vapor.

•  The dry ingredients mixing with the wet ingredients.

Guided Notes

PHYSICAL CHANGE

• Physical Changes result when there is a re-arrangement of

the molecules of a substance. The molecules themselves
stay the same.

• Ex: Changes in state of matter, shape, size, volume, mass,

weight, and density.

cambio físico
chanjman fizik
mudança física

CHEMICAL CHANGES

• Chemical changes occur when the molecules of a

substance are separated or joined and changed into a
new substance with new properties.

• Ex: Bubbling and fizzing, light production, smoke,

and presence of heat.

cambio químico
chanjman chimik
mudança química

Key Indicators of Each Type of Change

Physical Change Indicator

Chemical Change Indicator

• NO New Substances

formed!

• Can be reversed.
• Ex: Change to State of

Matter.

• NEW Substance

Formed!

• Can’t be reversed.
• Production of a NEW

Color, Odor, Energy,
Gas.

How Temperature Affects Chemical Reactions

• The rate of a chemical reaction will INCREASE when

heat is added.

• The rate of a chemical reaction will DECREASE when

heat is removed.

Law of Conservation of Mass
•Mass cannot be created or
destroyed, just changed from
one form to another.

Ley de conservación de la masa
lwa konsèvasyon mas la
Lei da conservação de massa

Categorize

Options (16)

NaCl (table salt) dissolves in water

Ag (silver) tarnishes

Jay cuts an apple

Heat changes H2O to steam

Baking soda reacts to vinegar

Fe (Iron) rusts

Alcohol evaporates

Ice melts

Milk goes bad (sours)

sugar dissolves in water

wood rots (goes bad)

pancakes cook.

grass grows

inflating a tire

food is digested

paper towel abssorbs water

Organize these options into the right categories

Physical Change

Chemical Change

Open Ended

Marijah places an alka-seltzer tablet into a cup of hot water and another tablet into a cup of cool water.

Which cup will finish the reaction first? Why?

Open Ended

Michael Sheets measured the mall of the alka-seltzer tablet and the cup of water before the reaction. After the reaction, some of the mass was missing.

What happened to the missing mass?

Multiple Choice

Your friend decides to toast a piece of the bread, but leaves it in the toaster too long.  The bread is black and the kitchen is full of smoke.

• Physical Change

• Chemical Change

Multiple Choice

Your forgot to dry the bread knife when you washed it and reddish brown spots appear on it.

• Physical Change

• Chemical Change

Multiple Choice

You blow dry your hair.

• Physical Change

• Chemical Change

Multiple Choice

When baking biscuits or bread, the baking powder reacts to release carbon dioxide bubbles which cause the dough to rise.

• Physical Change

• Chemical Change

Open Ended

Exit Ticket

How can you use evidence to determine if a change is physical or chemical?

Poll

For this lesson, rate your understanding of the material from 1-4.

• Level 1: I would've understood better

• Level 2: I kind of understood it, but

• Level 3: I was able to complete this

• Level 4: I was able to help others do