Metallic Bonding/ alloys

Question 1

Why are metals used in pans and electrical wires?

Answer 1

• They are good conductors of heat + electricity.
• Have sea of delocalised electrons that move THROUGHOUT the positive ions, carrying charge.

Question 2

What does malleable mean?

Answer 2

• Can be bent/ pressed into shape.

Question 3

Why are metals malleable?

Answer 3

• Their fixed layers are able to slide when a force is applied.

Question 4

What is a “pure metal”?

Give an example of one

Answer 4

A material made of atoms from one type of element eg. zinc.

Question 5

What is an “ alloy”?

Answer 5

A mixture of elements, including at least 1 metal.

Question 6

Why are alloys harder than pure metals?

Answer 6

• Different atom sizes distorts the layers, making them more difficult to slide over each other.
• Making them harder than pure metals.

Question 7

Explain why steel, an alloy, is hard.

Answer 7

• Iron is very soft
• Iron + tungsten form steel
• Adding tungsten distrupts layers of iron as tungsten is much larger.
• Layer are unable to slide, makes material stronger.

Question 8

What is a giant metallic lattice?

Answer 8

• Regularly pattern of ions surrounded by sea of delocalised electrons.

Question 9

Why do metals have high melting + boiling points?

Answer 9

• Strong electrostatic forces of attraction (mettalic bonds) between positive ion and negative electrons.
• Requires a lot of energy to break.

Question 10

What is the melting point of magnesium in comparison to sodium?

Answer 10

• Magnesium = Higher
• More delocalised electrons. Stronger electrostatic forces (metallic bonds .)

Question 11

What is metallic bonding?

Answer 11

• Layers of positive ions held together by a sea of delocalised electrons.

Question 12

Q.)

Are metals examples of giant structures ?

Answer 12

Yes. It repeats
Giant metallic lattice

Question 13

Q.)

Both grpahite and metals have layers, how do these DIFFERENT types of layers affect their propeties.

Answer 13

• Graphite is soft and slippery: Weak forces between layers that can slide easily over each other.
• Metals are malleable and ductile: layers of ions can slide easily.

Question 14

Q.)

Explain why alloys are harder than pure metals. (3)

Answer 14

• Alloys have atoms of different sizes
• This distrupts the lattice
• This means the layers can’t slide easily.

Question 15

Q.)

Copper is a metal. Explain how it conducts electricity.

Answer 15

• Contains a sea of delocalised
• electrons from highest energy level of atoms can move throughout structure.

Question 16

Q.)

Why do the metal ions slide over each other easily?

Answer 16

• No attraction between ions so they can move away from each other.

Question 17

Q.)

Why does a metal not shatter when a force is applied to it?

Answer 17

• Strong electrostatic force of attraction (metallic bond) between sea of delocalised electrons and positive ions.

Question 18

Describe the structure and bonding in metals.

Answer 18

1.) Giant metallic structure
2.) Regular positively charged ions
3.) Sea of delocalised electrons
4.) Outer shell electrons can move throughout structure.
5.) Force of attraction

Question 19

Q.)

Suggest why the conductivity might be decreased when copper reacts with oxygen.

Answer 19

• Copper oxide formed
• Oxide ions may reduce the flow of electrons.

Question 20

Why are metals good conductors of heat and electricity?

Answer 20

• Have delocalised electrons that can flow throughout the structure and carry charge and thermal energy.