Bonding, Structures and Properties

Question 1

In an ionic bond, what happens to electrons?

Answer 1

Electrons are transferred from one atom to another

This results in the formation of two oppositely charged ions.

Question 2

What structure do ionic compounds form?

Answer 2

Giant ionic lattice

The structure is held together by electrostatic attraction between oppositely charged ions.

Question 3

The strength of an ionic bond is determined by which two factors?

Answer 3

• How closely the ions are packed into the lattice
• The charge on the ions

These factors influence the overall stability of the ionic compound.

Question 4

Covalent bonds are formed between which types of atoms?

Answer 4

• Non-metallic atoms

In covalent bonding, atoms share valence electrons to achieve full outer shells.

Question 5

What are the two types of structures that covalent bonding can form?

Answer 5

• Simple molecular
• Giant covalent

Question 6

What is electronegativity?

Answer 6

The tendency of an atom to attract a bonding pair of electrons

It describes how strongly an atom is attracted to a negative charge

Question 7

What is the Pauling scale used for?

Answer 7

To measure electronegativity

Fluorine has the highest value, while Caesium has the lowest.

Question 8

What is a polar bond?

Answer 8

A bond with an uneven distribution of electrons

This results in partial charges on the atoms involved.

Question 9

What are the three types of intermolecular forces?

Answer 9

• Temporary dipole interactions
• Permanent dipole interactions
• Hydrogen bonds

These forces affect the physical properties of substances

Question 10

What type of intermolecular force is the weakest?

Answer 10

Temporary dipole interactions

Also known as London dispersion forces, these forces arise due to an uneven distribution of electrons

Question 11

What are hydrogen bonds?

Answer 11

Strong intermolecular forces that occur when hydrogen is bonded to a very electronegative atom

These bonds have a significant impact on the physical properties of water

Question 12

What happens to metal atoms during metallic bonding?

Answer 12

They lose their outer shell (valence) electrons

This results in positively charged metallic cations.

Question 13

What charge do group 1 elements typically form?

Answer 13

+1

Group 1 elements lose one electron to achieve a full outer shell.

Question 14

What is the charge of a hydroxide ion?

Answer 14

-1

Hydroxide is a common compound ion in ionic compounds.

Question 15

To work out the formula of an ionic compound, what can be done with the charges on each species?

Answer 15

The charges can be crossed over

Sometimes the ratio will then need to be simplified to get the final compound formula

Question 16

What is a physical property?

Answer 16

A feature of a substance that can be measured or described without changing its chemical nature

Examples include melting/boiling point, thermal conductivity, appearance.

Question 17

What is a chemical property?

Answer 17

A feature of a substance that describes how it behaves when it reacts with other substances and changes its chemical identity

Examples include pH, reactivity, and flammability.

Question 18

List the physical properties of metals.

Answer 18

• High melting and boiling points
• High electrical and thermal conductivity
• High malleability and ductility
• High density
• Normally lustrous (shiny)

These properties are due to the structure and bonding of metals.

Question 19

What does high melting and boiling points in metals indicate?

Answer 19

Strong attraction between metallic cations and delocalised electrons requires a lot of energy to break

Group 2 metals have higher melting points than group 1 due to more electrons involved in bonding.

Question 20

Define malleable

Answer 20

a material that can easily be deformed by means of compressive forces

malleable materials can be hammered into sheets

Question 21

Define ductile

Answer 21

a material that can easily be deformed by means of tensile forces

Ductile materials can be drawn into wires

Question 22

What are the physical properties of ionic compounds?

Answer 22

• High melting and boiling points
• Electrical conductivity (when molten or in solution)
• Soluble in water
• Brittle

These properties are due to the strong electrostatic forces between ions.

Question 23

What does high melting and boiling points in ionic compounds indicate?

Answer 23

Due to the strong electrostatic forces between ions

Ionic compounds have high melting and boiling points.

Question 24

What is the solubility of ionic compounds in water?

Answer 24

Soluble

Water is a polar solvent, effective at dissolving polar molecules and ionic compounds.

Question 25

List the **physical properties of simple covalent substances**.

Answer 25

* Low melting and boiling points * Poor electrical conductivity * Some are soluble in water (depends on polarity) * Soft ## Footnote These properties arise from weak intermolecular forces.

Question 26

What does **low melting and boiling points** in simple covalent substances indicate?

Answer 26

Only the intermolecular forces need to be broken, which are much weaker ## Footnote Strong covalent bonds hold the molecules together.

Question 27

What are the **physical properties of giant covalent substances**?

Answer 27

* High melting and boiling points * Electrical insulators * Hard and brittle * Poor solubility in water ## Footnote These properties are due to the strong covalent bonds in the lattice structure.

Question 28

What does **high melting and boiling points** in giant covalent substances indicate?

Answer 28

Very high melting points as all of the covalent bonds need to be broken ## Footnote Requires a huge amount of energy.