2.2 ELECTRONS,BONDING & STRUCTURE

Question 1

State the number of electrons that can fill the first four shells

Answer 1

Question 2

Shape of s-orbitals

Answer 2

• Spherical shape

Question 3

Shape of p-orbitals

Answer 3

• 3D dumb-bell shape

Question 4

How many electrons can an s-orbital hold?

Answer 4

2

Question 5

How many electrons can a p-orbital hold?

Answer 5

6

Question 6

How many electrons can a d-orbital hold?

Answer 6

10

Question 7

Which shells contain s-orbitals?

Answer 7

• All shells

Question 8

Which shells contain p-orbitals?

Answer 8

• From n=2 upwards

Question 9

Which shells contain d-orbitals?

Answer 9

• From n=3 upwards

Question 10

Does 4s or 3d have a higher energy level?

Answer 10

• 3d has a higher energy level so is filled first

Question 11

Define ionic bonding

Answer 11

• The electrostatic attraction between positive and negative ions

Question 12

Describe giant ionic lattice structure

Answer 12

• Repeating pattern of oppositely charged ions with strong electrostatic attraction in all directions

Question 13

Explain the melting/boiling point of a giant ionic lattice

Answer 13

• Strong ionic bonds in all directions means lots of energy needed to overcome these bonds, so has a high mp/bp

Question 14

Explain the electrical conductivity of a giant ionic lattice

Answer 14

• Giant ionic lattices can only conduct when melted/dissolved because ions are not mobile/cant move in the solid state

Question 15

Explain the solubility of a giant ionic lattice

Answer 15

• Giant ionic lattices are soluble in polar solvents (e.g water) because polar water molecules can interact/break apart the ions

Question 16

Define covalent bonding

Answer 16

• The strong electrostatic attraction between a shared pair of electrons and the nucleus of the bonded atoms

Question 17

Define dative covalent bonding

Answer 17

• When one atom provides both of the shared electrons in a covalent bond

Question 18

What type of bonding does average bond enthalpy measure?

Answer 18

• Covalent bond

Question 19

Compare the relative repulsion strengths of bonded pairs of electrons and lone pairs of electrons

Answer 19

• Lone pair repulsion is greater than bonded pair repulsion

Question 20

Draw the shape and bond angle of a linear molecule.

Answer 20

Question 21

Draw the shape and bond angle of a non-linear molecule.

Answer 21

Question 22

Draw the shape and bond angle of a trigonal planar molecule.

Answer 22

Question 23

Draw the shape and bond angle of a pyramidal molecule.

Answer 23

Question 24

Draw the shape and bond angle of a tetrahedral molecule.

Answer 24

Question 25

Draw the shape and bond angle of a **octahedral** molecule.

Answer 25

Question 26

Define **electronegativity**

Answer 26

- An atoms **ability** to **attract** the **bonding electrons** in a **covalent** bond

Question 27

State the **most electronegative** element

Answer 27

- Fluorine

Question 28

State and explain **electronegativity** across a **period**.

Answer 28

- Electronegativity **increases** - **Atomic charge (proton number)** increases so there is a **stronger attraction** between **nucleus** and **bonded electrons** in a covalent bond

Question 29

State and explain **electronegativity** up a **group**.

Answer 29

- Electronegativity **increases** - **Atomic radius decreases** due to **less shells** so theres **less electron sheilding** - **Atomic radius decreases** due to **less shells** so shorter distance between **nucleus** and **bonded electrons** in a covalent bond - Therefore, **stronger attraction**

Question 30

Define **polar bond**

Answer 30

- When a **difference** in **electronegativitys** causes a **perminant dipole**

Question 31

State 2 requirements for a molecule to be **polar**.

Answer 31

1) Must have a **polar bond** (perminant dipole) 2) Must be **assymetrical** so **dipoles** dont cancel out

Question 32

State the three types of **intermolecular forces**

Answer 32

1) **London/induced temporary dipole-dipole** forces 2) **Perminant dipole-dipole** forces 3) **Hydrogen** bonding

Question 33

Which types of molecules have **london/induced temporary dipole-dipole** forces?

Answer 33

- **ALL** molecules

Question 34

Which types of molecules have **perminant dipole-dipole** forces?

Answer 34

- **Polar** molecules

Question 35

Which types of molecules have **hydrogen** bonding?

Answer 35

- Only molecules with **H and O, N, F**

Question 36

Define **hydrogen** bonding

Answer 36

- A type of **perminant dipole-dipole** interaction between an **electron deficient hydrogen (δ+)** and a **lone pair** of electrons on **O,F,N**

Question 37

State what the **strength** of **London/induced temporary dipole-dipole** forces depends on

Answer 37

- Number of **electrons** - **More electrons** = **stronger** london forces

Question 38

Draw **hydrogen bonding** between **water** molecules

Answer 38

Question 39

Explain the **2** effects of **hydrogen bonding** on **water properties**

Answer 39

- **Higher** than expected **MP/BP** because of **additional** **hydrogen bonding** that requires **more energy** to **overcome** - **Ice** is **less dense** than water because **additional** **hydrogen bonding** gives it an **open lattice structure**

Question 40

Describe the **solid structure** of **simple molecular lattices**

Answer 40

- **Covalent bonds** between **atoms** - **Attracted** by **intermolecular forces** (NAME IT)

Question 41

Explain the **electrical conductivity** of **simple molecular lattices**

Answer 41

- **Not conductive** because there are **no charged particles** that are **free** to **move**

Question 42

Explain the **solubility** of **simple molecular lattices**

Answer 42

- They are **non-polar** so only **soluble** in **non-polar solvents** as **weak london forces** can form between **molecules** and **non-polar solvent** to **break** apart the **simple molecular lattice**

Question 43

Explain the **MP/BP** of **simple molecular lattices**

Answer 43

- **Relatively low MP/BP** because of **relatively weak intermolecular forces** (NAME IT) that **do not** require great amounts of **energy** to **overcome**