Bonding

Question 1

Ionic bonds

Answer 1

a strong electrostatic
attraction between oppositely charged ions

Question 2

Covalent bond

Answer 2

when a pair of electrons is shared between two non-metal atoms leading to noble gas electronic configurations

Question 3

Metallic bonding

Answer 3

the strong electrostatic attraction between the positive ions (metal name) in a giant
metallic lattice and a ‘sea’ of delocalised electrons

Question 4

Diamond bond

Answer 4

Each carbon atom forms

4 strong covalent rigid bonds with each other

forming a tetrahederal arrangement

giving rise to a 3-dimensional macromolecular structure

Question 5

Graphite bond

Answer 5

Each carbon atoms forms

3 strong covalent bonds with each other

forming layers of flat hexagonal rings

Question 6

Silicon Dioxide bond

Answer 6

Each silicon atom is covalenty bonded to 4 Oxygen atoms

Each oxygen atom is bonded to 2 silicon atoms by strong rigid covalent bonds

forming a tetrehedral arrangement

giving rise to a 3-dimensional macromolecular structure

Question 7

intermolecular forces def

and property

Answer 7

forces of attraction between molecules e.g Van der Waals

they are weak and easy to overcome at lower temperatures

Question 8

intramolecular forces def

and property

Answer 8

forces of attraction found inside molecules
e.g covalent bonds

strong, do not break during melting or boiling

Question 9

Diamond properties

Answer 9

High melting and boiling point (strong intramolecular)

Very Hard

Poor electrical conductor

Question 10

Graphite properties

Answer 10

Electrical conductor

Lubricant (weak van der waals layer slide over each other)

Question 11

Diamond vs Graphite
properties and uses

Answer 11

Properties of diamond:
- Does not conduct electricity
- very hard substance
- transparent crystal which sparkles in light
(Silicon oxide has same properties)

Uses of diamond:
- Used for cutting rocks

Properties of Graphite:
- Conducts electricity
- Soft and slippery
- A grey-black shiny solid

Uses of Graphite:
- Used as a lubricant
- Used as an electrode

Question 12

Properties of metals

Answer 12

High melting points

Hard

Usually high density

Goold electrical conductivity as molten, aqueous or solid

Malleable and ductile

Question 13

Simple molecular covalent bonds properties

Answer 13

Low melting and boiling points (weak intermolecular)

Poor electrical conductor

Question 14

Ionic compounds properties
(physical)

Answer 14

• Good electrical conductivity when aqueous or molten but poor when solid
• High melting and boiling points
• Soluble in water
• Brittle

Question 15

What is arrangement in ionic compound:

Answer 15

Giant ionic crystal lattice:

Regular arrangement of
alternating positive and negative ions held together by strong electrostatic forces of attraction

Question 16

Why ionic compounds have higher melting points than covalent bonds

(mark scheme answer)

Answer 16

• ionic bonds (forces of attraction between ions) are stronger than attractive forces between molecules
• ionic bonds need more energy to break than attractive
  forces between molecules.

Question 17

Element def

Answer 17

Substance that is made up of atoms with same atomic number

Or

Substance that cannot be split up by chemical means

Question 18

Atom def

Answer 18

Smallest part of an element that can exist as a stable entity

Question 19

Ion def

Answer 19

a species with a positive or negative charge

Question 20

Compound def

Answer 20

A pure substance, which contains two or more different elements chemically bonded together

Question 21

Molecule def

Answer 21

Smallest part of an element or a compound, which can exist alone under ordinary conditions

Question 22

Mixture def

Answer 22

Two or more substances that can be seperated by physical means

Question 23

Why do isotopes have same chemical properties

Answer 23

Same number of electrons

so they have same electronic configuration and same number of valence electrons in outer shell

Question 24

Allotropes

Answer 24

Different crystalline forms of the same element. They have the same chemical properties, but different physical properties.

Question 25

How ionic compounds conduct electricity

Answer 25

Contains ions (charged particles) which can move to transfer electricity in aqueous or molten state