Alloy and metals

Question 1

Explain 2 properties of pure metals

Answer 1

• maleable: arrangement of metal atoms are not perfect
  Metal atoms can slide and settle into new positions
• ductile: layers of metal atoms can slide and over one another
  -high melting and boiling point: F. O. A between closely packed metal atoms are very strong. More heat energy is required.

Question 2

Define allow

Answer 2

Ally os the combination of 2 or more elements with a fixed composition and the main element being a metal

Question 3

Why are alloys more resistant to corrosion

Answer 3

It prevents the formation of metal oxides on the metal surface. Additional elements added into pure metal will form a good protective layer of metal oxide which is non porous, and sticks to the metal surface. This prevents corrosion of metal.

Question 4

What is pewter made of

Answer 4

Antimony
Copper
Tin

Question 5

State 3 uses of duralumin and the property which supports its uses

Answer 5

Body of aeroplanes
Racing tracks
Electrical cables
-low density

Question 6

What alloy is used to make surgical instruments, cutleries and sinks?

Answer 6

Stainless steel

Question 7

State 2 properties of steel

Answer 7

Stronger and harder

Malleable

Question 8

What does bronze consist of?

Answer 8

Copper

Tin

Question 9

What does brass consist of?

Answer 9

Copper

Zinc

Question 10

What does duralumin consist of?

Answer 10

Aluminium
Copper
Magnesium
Manganese

Question 11

State a property of superconductors

Answer 11

They have low electrical resistance at very low temperature

Question 12

What is the main element in glass?

Answer 12

Silicon dioxide // silica

Question 13

State 3 properties of glass

Answer 13

Transparent
Waterproof
Heat insulator

Question 14

Explain the structure of glass?

Answer 14

1 silicon atom attaches to 4 oxygen molecules to form a tetragonal shape.
Each oxygen mol. attaches to 2 silicon atoms to form a macromolecule

Question 15

What type of glass is most suitable for lab apparatus?

Answer 15

Borosilicate glass

Question 16

Explain how fused glass is produced

Answer 16

Silicon dioxide is heated until completely molten and then cooled immediately. Silica does not crystalize completely and this resembles liquid state

Question 17

Name 2 glass which has high thermal coefficient of expansion

Answer 17

Fused glass

Borosilicate glass

Question 18

Explain how soda lime glass is formed

Answer 18

Silicon dioxide is heated with soda and limestone at 1500°c and cooled quickly.

Question 19

What is the function of sodium carbonate when making sodalime glass

Answer 19

To lower the melting point of silica

Question 20

What is borosilicate glass made of?

Answer 20

Boron oxide
Alluminium oxide
Soda
Limestone
Silica

Question 21

State 2 properties of borosilicate glass

Answer 21

Can withstand extreme temperature change

Resistant to chemical sttacks

Question 22

Why is lead crystal glass used to make chandeliers

Answer 22

It has high refractive index

Question 23

What is the synonym of lead crystal glass

Answer 23

Lead glass

Crystal glass

Question 24

How are ceramics made?

Answer 24

Clay is dried and baked at high temperature

Question 25

What is silicon carbide

Answer 25

A advanced ceramic

Question 26

Why is silicon carbide used to make brake disc

Answer 26

It can withstand high thermal shock | Can withstand high temperature

Question 27

What is another use of silicon carbide. why?

Answer 27

To make tungsten carbide rings. It is resistant to abrasions

Question 28

State 3 properties of ceramics and its uses

Answer 28

Chemically inert - plates / bowls Resistant to heat - lining of furnace Hard and strong - artificial hands/ dental implantation

Question 29

State 2 diff between glass and ceramics

Answer 29

Glass : ceramics Transparent : opaque Non porous : porous Lower melting point : higher melting point

Question 30

What is a composite material?

Answer 30

A material made by combining 2 or more non-homogenous substances that is a strengthening and matrix substance

Question 31

What are the uses of fibre glass?

Answer 31

Helmets | Car bumpers

Question 32

What are the benefits of using optical fibre.how?

Answer 32

It can transmit information without being influenced by electromagnetic disturbances. This is due to the diff refractive index of its components.

Question 33

What is the use use of copper(I) chloride in photochromic glass

Answer 33

As a catalyst to catalyse the recombine silver atoms and chloride gas.

Question 34

What is photochromic glass made of?

Answer 34

Glass (matrix) AgCl CuCl

Question 35

Why is advanced ceramics used in MRI?

Answer 35

It has superconductivity properties

Question 36

State 2 benefits of using reinforced concrete than its original components.

Answer 36

Higher compression strength Resistant to corrosion High stretching strength

Question 37

What happens when photochromic glass is exposed to UV rays

Answer 37

Silver chloride breaks down into silver atoms and chlorine gas.