Atmosphere and Materials Revision

What is the approximate proportion of gases in dry air?

• 78%

• nitrogen

• 0%

• oxygen

• 1%

• water

• 21%

• argon

• 0.04%

• carbon dioxide

Which of the following describes a polymer?

• A molecule made from many repeating units

• A single unit of a molecule made from many repeating units

• A hard material made when a soft starting material is heated in a kiln

• A material made from two or more different materials

Which of the following describes a monomer?

• A molecule made from many repeating units

• A single unit of a molecule made from many repeating units

• A hard material made when a soft starting material is heated in a kiln

• A material made from two or more different materials

Which of the following describes a ceramic?

• A molecule made from many repeating units

• A single unit of a molecule made from many repeating units

• A hard material made when a soft starting material is heated in a kiln

• A material made from two or more different materials

Which of the following describes a composite material?

• A molecule made from many repeating units

• A single unit of a molecule made from many repeating units

• A hard material made when a soft starting material is heated in a kiln

• A material made from two or more different materials

Organize the following materials into the correct categories

Groups:

(a) Polymer

,

(b) Ceramic

,

(c) Composite

• Reinforced concrete

• Terracotta

• PET (poly ethylene)

• Breathable, waterproof fabric

• Spandex

• Brick

• Glass

• Cellulose

• MDF (medium density fibreboard)

• DNA

• Nylon

MDF is a composite of ​ ​ (a)   and ​ (b)  

• glue
• wood fibres
• conrete
• steel

Reinforced concrete is a composite of ​ (a)   and ​ (b)  

• wood fibres
• glue
• steel
• concrete

Reinforced concrete is a composite material that has some properties from each of its constituents, steel and concrete. Steel and concrete are complementary because steel is strong under _________ while concrete is strong under compression. This makes reinforces concrete stronger than regular concrete.

Reinforced concrete is a composite material that has some properties from each of its constituents, steel and concrete. Steel and concrete are complementary because steel is strong under tension while concrete is strong under ___________. This makes reinforces concrete stronger than regular concrete.