Chemical Bonds

Question 1

Define an ionic bond

Answer 1

One atom donates one or more electrons to another atom. This makes one atom negative (anion) and the other positive (cation). This forms a very strong bond. This occurs in salts

Question 2

Define ion

Answer 2

An ion is a charged atom or group of atoms

Question 3

Define covalent bonds

Answer 3

A Covalent bond is a bond in which there is a sharing of one or more electrons with another atom.
They form the strong primary bonds in polymers

Question 4

Define and explain a metallic bond

Answer 4

In a metallic bond, the atoms donate one or more electrons to a ‘sea’ of electrons, which are shared by all the atoms. This sea of electrons is free to move and has a negative charge.

Question 5

What are positive metal ions referred to as in metallic bonding?

Answer 5

cations

Question 6

What are cations?

Answer 6

They are positive metal ions in metallic bonding

Question 7

what charge does the sea of electrons in metallic bonding have?

Answer 7

negative charge

Question 8

What do the positive metal ions/cations do in metallic bonding?

Answer 8

They are held together by the sea of negative electrons. this is the metallic bond

Question 9

What is the metallic bond exactly?

Answer 9

The cations are held together by the sea of negative electrons.

Question 10

How do the metal ions/cations arrange themselves in chemical bonding?

Answer 10

The ions arrange themselves into crystal lattice structures.

Question 11

What do metallic bonds provide an explanation to?

Answer 11

They explain the primary properties of metals

Question 12

What explains the primary properties of metals?

Answer 12

metallic bonds

Question 13

What properties are associated with metallic bonds? (4)

Answer 13

High strength, high melting points, good conductors of electricity, good conductors of heat

Question 14

Why do metals have high tensile strength and high melting and boiling points?

Answer 14

Because it takes a lot of energy and force to break metallic bonds

Question 15

Why are metals good conductors of electricity?

Answer 15

Electrons are free to move around in the ‘sea’ of electrons.
Electricity is the movement of electrons.

Question 16

Why are metals good conductors of heat?

Answer 16

because:
The electrons transmit heat vibrations throughout the metal quickly
- because the electrons are free to move around.
The metal ions are packed closely together so they can transmit heat vibrations from one ion to the next.

Question 17

How are the properties of malleability and ductility caused in metals?

Answer 17

they are caused by slipping between atoms in metallic bonds.

Question 18

Why are metals malleable and ductile?

Answer 18

Because:
An external force can cause the metal ions to move and slip into new positions within the crystal lattice - without breaking the metallic bond.
So, slip allows metals to deform plastically without breaking.

Question 19

What do higher forces do to metallic bonds?

Answer 19

Higher forces can break the metallic bonds causing fracture.

Question 20

What causes fracture in metallic bonds?

Answer 20

Higher forces break them

Question 21

What two factors determine how easily atoms can slip and how ductile they are?

Answer 21

1. The type of crystal structure
2. the amount and type of defects in the crystal structure