SCIENCE & the ARTS

CHEMICAL

vs

PHYSICAL

CHANGE

Constantine Brancusi, Romanian 1876 - 1957Mademoiselle Pogany II, 1925Polished bronze on limestone base17 x 7 ¼ x 9 3/8 in.

Shang dynasty, Anyang period, ca. 12th – 11th century BCERitual Wine-Pouring Vessel., (Guang) Bronze,7 ¼ x 8 x 4 13/16 in.

Chemical Change…

Patina… change that results in a new material being formed with different physical properties.

The change usually cannot be reversed.

Physical Change…

… change that results with no new material being formed; physical properties stay the same.

The change can be reversed.

Nele Azevedo, BrazilMelting Men, 20091000 ice carvingsBerlin

Physical or Chemical Change?

Chemical.

When metal that contains iron comes in contact with water and oxygen, a new material called iron oxide (rust) is formed.

Aussie BlueyRed Rust Sculpture

Physical or Chemical Change?

Physical. The melted form is not a new material—it is still crayon.

Also, you can reverse this change by melting the wax and reforming it into a crayon shape.

Bob Bonanno, AmericanRainbow Bridge, 2008Melted crayons

Physical or Chemical Change?

Chemical.

As wood burns, carbon is formed. As carbon burns, it combines with oxygen to give off carbon dioxide gas.

Burnt wood cannot be returned to its original form.

Kanayo Ede, NigerianSatchmoBurnt wood24 x 48 in.

Physical or Chemical Change?

Physical.

No new material is created and this change can be reversed by washing off the paint.

Jackson Pollock in his studio

Physical or Chemical Change?

Chemical. The dark substance is a new material called carbon that forms when the sugar in the bread is exposed to too much heat.

Ingrid Falk, Gustavo AguerreThe Toaster

How can you tell the difference between a chemical and physical change?

Form a Hypothesis

Test Your Hypothesis

Bag 1: Mix 2 tsp. of borax & 1 tsp. water.

Bag 2: Mix 4 tsp. of Elmer’s Glue & 1 tsp. of water.

Pour Bag 1 into Bag 2; seal, and mix.

Did you observe a physical or chemical change?

Summary

How is a chemical change represented by this guang?

patina

Summary

How is a physical change represented by the melting ice men?

No new material is created, and the water can be refrozen.

Reflection

How can a background in science help an artist?

Dale Chihuly

September Grassby James Taylor

Well, the sun’s not so hot in the sky today,And you know I can see summertime slipping on away,A few more geese are gone, a few more leaves turning red, But the grass is as soft as a feather in a featherbed,So I’ll be king and you’ll be queen,Our kingdoms gonna be this little patch of green.http://www.youtube.com/watch?v=QZL-6KyL72k

Sue Loder, U.K.Autumn TreesOil on canvas

Notes

• http://www.youtube.com/watch?v=QZL-6KyL72k

• James Taylor’s song “September Grass”

• Have students identify a physical AND a chemical change mentioned in the lyrics