Structure and Bonding broad sheet questions

Question 1

What is an ion?

Answer 1

An atom with a charge.

Question 2

What is covalent bonding?

Answer 2

This is where atoms share electrons to obtain a full outer shell.

This is where 2 NON METALS JOIN.

Question 3

What holds atoms together in a covalent bond?

Answer 3

The electrostatic attraction between positive nucleus’ and the shared pair of electrons.

Question 4

How are ions formed?

Answer 4

Atoms that loose electrons (metals) gain a positive charge.
Atoms that gain electrons(non-metals) gain a negative charge.

IONIC BONDS FORM BETWEEN NON-METALS AND METALS.

Question 5

Why do ionic compounds have a high melting point?

Answer 5

Because regular arrays of positive and negative ions contain many strong electrostatic attractions which require a large amount of heat energy to over come. (break)

Question 6

Describe the difference between an allotrope and an isotope?

Answer 6

Allotrope: Different structures of the same element.

Isotope: Different mass atoms of the same element.

Question 7

Explain why metals are malleable?

Answer 7

Because layers of electrons can slide over each other. The ‘sea of electrons’ can change shape but does not break which is why it can bend.

Question 8

Name some properties of metals:

Answer 8

• solid
• high melting point
• shiny
• high density
• Good conductor of heat & electricity
• malleable
• ductile

Question 9

Property’s of non-metals:

Answer 9

• solid liquid or gas
• low melting points
• Brittle
• low density
• poor conductor of heat & electricity

Question 10

What is metallic bonding?

Answer 10

When metals contain a regular array of positive metal ions surrounded by delocalised ‘sea of electrons’.

OOOOOOO
OOOOOOO (Positive ions with electrons
OOOOOOOO. Surrounding it)

Question 11

What is a metallic bond?

Answer 11

A metallic bond is the electrostatic attraction between a positive ion and the delocalised sea of electrons.

2 METALS FORM A METALLIC BOND.

Question 12

Explain why metals are good condoctors of electricity?

Answer 12

Metals have electrons which are free to move in the delocalised ‘sea of electrons’ so as moving electrons can carry and transfer charge it makes metals conduct.

Question 13

How does the charge on the metal ion effect strength and conduction of metal?

Answer 13

Higher charged ion = more delocalised electrons which= stronger metallic bonds and better conductor of electricity.

Question 14

What are the 3 types of chemical bonds and what atoms do they form between?

Answer 14

Ionic bonds (metal &a non-metal)

Covalent bonds (non-metal & non-metal)

Metallic bonds (metal & metal)

Question 15

Explain why simple covalent molecules do not conduct electricity ?

Answer 15

Simple molecules have no charged particles to carry current. Electrons are involved in covalent bonds between molecules and cannot be used to carry charge.

Question 16

What is a molecule?

Answer 16

A small group of atoms that go around each other.

Question 17

What are simple molecular compounds?

Answer 17

Simple molecular compound have strong covalent bonds holding the atoms together in the molecule. As they normally form gases and liquids they have weak intermolecular forces between the molecules.

Properties: gases or liquid, low melting point, do not conduct electricity.

Question 18

Explain why graphite conductus electricity and diamond doesn’t?

Answer 18

Because Graphite forms a layered structure. Between the layers are week intermolecular forces containing free electrons which can move between the layers.
All the electrons in diamonds are involved in strong covalent bonds so do t have free electrons to carry charge.

Question 19

Describe the structure of diamond

Answer 19

Every carbon atom is bonded to 4 other carbon atoms with a strong covalent bond. This looks like a giant structure of tetrahedral carbons.

Question 20

Describe the structure of graphite

Answer 20

Every carbon atom is bounded to 3 other carbon atoms with strong covalent bonds to form hexagons which join to form layers. These layers are held together with week forces.

Question 21

What is a polymer and how are they made?

Answer 21

Polymers are very large molecules that form chains. They are made in polymerisation reactions from monomers.

Monomer -> polymer

Question 22

How and why are the properties of polymers different to those of simple molecules?

Answer 22

How: polymers are low melting point solids which can be moulded into shapes. Simple molecules tend to be liquids or gas.

Why: Polymers are very large molecules with large intermolecular forces. They form chains which get tangled up.

Question 23

Describe the structure of an ionic compound.

Answer 23

Ionic compounds form lattices which are regular arrays of positive and negative ions held together with strong electrostatic attractions(ionic bonds) to give a giant structure.

ALL IONIC COMPOUNDS FORM LATTICES AND CRYSTALS WHEN SOLID.

Question 24

What is the difference in bonding between a simple covalent molecule and a giant covalent structure?

Answer 24

Simple covalent molecule: Atoms are held together with covalent bonds in molecules. Molecules are held together with weak intermolecular forces .

Giant covalent structure: every atom is held to every other atom with a strong covalent bond. This creates a giant lattice all held together with strong covalent bonds.

Question 25

Describe the the structure and conductivity of a simple covalent molecule.

Answer 25

Simple covalent molecules are discrete units of atoms. The atoms are held together with strong covalent bonds to form a molecule. The molecules are held together with weak intermolecular forces.

Question 26

Explain why giant covalent structures are solids with high melting points.

Answer 26

Every atom is held to another atom with strong covalent bonds. Many strong covalent bonds require a large amount of heat energy to over come. Electrons are involved in covalent bonding between atoms and are not available to carry charge.

Question 27

Explain why simple molecules have low melting points.

Answer 27

Simple covalent molecules have weak intermolecular forces holding the molecules together. These weak intermolecular forces only require a small amount of heat energy to over co them. The strong covalent bonds with in molecules are not broken in changes of states.

Question 28

Why are ionic compounds able to conduct electricity when molten or dissolved?

Answer 28

In an ionic lattice the ions are fixed in place so cannot carry charge. When the ions are dissolved in solution or are molten they become free to move. Moving ions can transfer charge so the material can conduct electricity.

Question 29

What is a giant metallic structure.

Answer 29

The structure of a metal consists of a regular arrangement of metal ions surrounded by a sea of delocalised electrons.

Question 30

Where are covalent bonds found?

Answer 30

In 2 types of structures simple molecules and giant covalent structures.

Question 31

How are metals and non metals different.

Answer 31

Metals and no metals are different because metals have extra electrons their outer shell.

Question 32

What is the delocalised sea of electrons?

Answer 32

Because metals have extra electrons so when they form metallic bonds each metal atom gives its outer electrons to form a delocalised sea of electrons