Covalent And Metallic Bonding CHAP 3

Question 1

What is Metallic Bonding?

Answer 1

Metallic bonding is the electrostatic forces of attraction between positive metal ions and sea of delocalised electrons.

Question 2

Describe how metallic bonding works.

Answer 2

Metal atoms loses their valence electrons to form cations (postively charged ions). they do this so they could achieve the stable electronic structure of noble gas. these electrons are free to move throughout the metal lattice and are said
to be delocalised.

Question 3

Are metallic bonds strong or weak

Answer 3

Metallic bonds are strong.

Question 4

Name all the physical properties of metal

Answer 4

1. High melting and boiling point.
2. Mallaeble and Ductile.
3. Good conductor of heat and electricity when in molten or solid state.

Question 5

Why are metals malleable and ductile.

Answer 5

When force is applied, the layers of metal ions slide pass each other. the sea of delocalised electrons adjsut themselves to prevent repulsion betweem the metal ion.

Question 6

What is the definition of Alloy?

Answer 6

Alloy is a mixture of a metal with one or more other elements.

Question 7

Why are alloy strong and hard?

Answer 7

Different elements have different atomic sizes, Hence, different size atoms disrupt the orderly arrangement of pure metals, making layers of atoms difficult to slide pass one another when force is applied. hence, alloys are harder and stronger than pure metal.

Question 8

Metallic bonding is the bonding within..

Answer 8

Within metals

Question 9

What constitutes to the sea of electrons in metallic bonding?

Answer 9

The electrons in the valence shell.

Question 10

Simple covalent molecules have..

Answer 10

have a simple covalent structure and weak intermolecular forces of attraction.

Question 11

during boiling and melting, what is broken and what remains intact for Simple Covalent Molecules.

Answer 11

weak intermolecular forces of attraction is broken down while the covalent bond remains intact

Question 12

Is the covalent bond within a molecule weak or strong

Answer 12

Strong, it remains strong.

Question 13

What are the 5 physcial properties of simple covalent structure?

Answer 13

1. low melting and boiling point.
2. does not conduct electricity at any state.
   3.usually insoluble in water and soluble in organic solvents.
3. exists as solid/liquid at room temperature and pressure.
4. High volatitly.

Question 14

Why does simple covalent bond have low MP/BP

Answer 14

As only a small amount of heat energy has to be absorbed to overcome the weak intermolecular forces of attraction.

Question 15

Why does simple covalent bond not conduct electricity at any state?

Answer 15

As there are no free electrons nor mobile ions to move to carry electric current to conduct electricity.

Question 16

List 2 examples of GIANT covalent structure/molecule

Answer 16

Graphite and Diamond

Question 17

What is the structure of Diamond?

Answer 17

In diamond, each carbon atom is joined by 4 other carbon atom by strong covalent bonds.

Question 18

What is the 4 properties of Diamond?

Answer 18

1. High Melting and Boiling point ( mp 3500 bp 4800)
   2.Hard
   3.insoluble in water and organic solvent.
2. does not conduct electricity at all.

Question 19

Why does diamond have high melting and boiling point?

Answer 19

As large amount of heat energy is needed to overcome the strong covalent bonds between the carbon atoms of diamond.

Question 20

Why is diamond hard

Answer 20

The four valence electrons of each carbon atom participate in the formation of very strong covalent bonds hence Diamond is hard due to its strong covalent bonding and tightly packed crystal structure.

Question 21

What is graphite made of

Answer 21

graphite is made up of layers of carbon atoms

Question 22

Describe the structure of graphite

Answer 22

within each layer, each carbon atom is joined by 3 other carbon atoms by strong covalent bond to form hexagonal rings.

Question 23

What are the attraction between the giant covalent molecule

Answer 23

Weak intermolecular forces of attraction exists between layers.

Question 24

What are the 3 properties of Graphite?

Answer 24

1. High melting and boiling point.
2. soft and slippery and layers can slide over each other
3. good conductor of electricity as it has mobile electrons within each layer.

Question 25

Uses of diamond and graphite?

Answer 25

Diamond : to make jewellery, and tools for drilling and cutting

Graphite: for pencil ‘lead’ and as lubricants for engines.

Question 26

What is a molecule?

Answer 26

A molecule is form when two or more atoms are joined together by covalent bond.

Question 27

What is a diatomic molecule?

Answer 27

A diatomic molecule is a molecule that is made up of two atoms joined by covalent bond.

Question 28

How is covalent bond form?

Answer 28

It is a bond that forms when atom share valence electrons to form a molecule

Question 29

Covalent bond is formed between?

Answer 29

Covalent bond is formed between non-metals.

Question 30

Covalent bond attraction

Answer 30

creation of a bond due to the electrostatic attraction between the shared electrons and the positively charged nuclei of both atoms involved.

Question 31

What are elements

Answer 31

elements are substances that cannot be broken down into simpler substances and it is made up of one type of atom only.

Question 32

What are compounds

Answer 32

Compounds are substances that are made up of two or more types of elements chemically joined together