Materials: Topic 1, Introduction and Bonding

Question 1

The four main types of materials

Answer 1

Ceramics, metals, composites, polymers

Question 2

The subgroups of metals

Answer 2

Ferrous, nonferrous, amorphous

Question 3

Examples of ferrous metals

Answer 3

Steels, stainless steels, tool and die steels, cast irons

Question 4

Examples of nonferrous metals

Answer 4

Aluminium, copper, titanium, tungsten

Question 5

The three types of plastics

Answer 5

Thermoplastics, thermosets, elastomers

Question 6

Examples of ceramics

Answer 6

Oxides, nitrates, carbides, glasses, glass ceramics, graphite, diamond

Question 7

Examples of composites

Answer 7

Reinforced plastics, metal-matrix, ceramic matrix, laminates

Question 8

Are material structure and it’s properties related?

Answer 8

Yes! Through the structure property relationship

Question 9

What are the unit prefixes in meters for atomic structure and bonding, micro structure, and macro structure.

Answer 9

Atomic structure and bonding = nano meters, micro structure = micro meters, macro structure = micro - milli structure.

Question 10

What is primary bonding? What are the different types?

Answer 10

The transfer or sharing of electrons. Types: Ionic, covalent and metallic

Question 11

What is secondary bonding? What are the different types?

Answer 11

Weak attraction between atoms, no transfer or sharing of electrons. Type: Van der Waals

Question 12

What is it all about?

Answer 12

BONDING

Question 13

Explain Ionic bonding between chlorine and magnesium

Answer 13

Magnesium ‘gives up’ an electron to each of two chlorine
atoms to form MgCl2.
•The magnesium has lost electrons and becomes +ve charged
•The chlorine atoms gain electrons and become -ve charged
•Hence chlorine is attracted to magnesium and bonding occurs
•Bond is non-directional: positively charged ions will be attracted to any
adjacent negatively charged ion.

Question 14

Ionic compound properties

Answer 14

• High melting and boiling points - Ionic bonds
are very strong - a lot of energy is needed to
break them. So ionic compounds have high
melting and boiling points.
• Conductive when liquid - Ions are charged
particles, but ionic compounds can only
conduct electricity if their ions are free to move.
Ionic compounds do not conduct electricity
when they are solid - only when dissolved in
water or melted.

Question 15

Is there more to life?

Answer 15

No

Question 16

Material classification is largely defined by:

Answer 16

Their bonding types

Question 17

Main type of bonding in plastics

Answer 17

Covalent

Question 18

Main type of bonding in ceramics

Answer 18

Ionic

Question 19

Main type of bonding in metals

Answer 19

Metallic

Question 20

Main type of bonding in semiconductor

Answer 20

Covalent

Question 21

If your happy and you know it

Answer 21

clap your hands!