2.2

Question 1

What is an atomic orbital?

Answer 1

A region around the nucleus that can hold up to 2 electrons with opposite spins.

Question 2

What is the shape of s-orbitals?

Answer 2

spherical

Question 3

How many s-orbitals does each shell contain?

Answer 3

1

Question 4

What is the shape of p-orbitals?

Answer 4

Dumb-bell

Question 5

How many p-orbitals does each shell contain from n=2?

Answer 5

3

Question 6

How many d-orbitals does each shell contain from n=3?

Answer 6

5

Question 7

How many f-orbitals does each shell contain from n=4?

Answer 7

7

Question 8

What is a sub-shell?

Answer 8

A group of the same type of orbitals within a shell (e.g. 2p)

Question 9

What is the order of orbital filling?

Answer 9

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 …

Question 10

How do orbitals fill?

Answer 10

In order of increasing energy

Question 11

Why does the 4s sub-shell fill before the 3d sub-shell?

Answer 11

The 4s sub-shell has a lower energy level

Question 12

Why do the 2 electrons in an orbital have to have opposite spins?

Answer 12

Opposite spins help to counteract the repulsion between the negative charges.

Question 13

How do electrons fill an orbital?

Answer 13

Orbitals with the same energy are occupied singly until there are no further orbitals available at the same energy level

Question 14

How can electron configurations be written in shorthand?

Answer 14

[Previous noble gas] plus additional outer electron sub-shells.

Question 15

Where is the s-block on the periodic table?

Answer 15

left block of two groups

Question 16

Where is the p-block on the periodic table?

Answer 16

right block of six groups

Question 17

Where is the d-block on the periodic table?

Answer 17

centre block of ten groups

Question 18

Why does the 4s sub-shell empty before the 3d sub-shell?

Answer 18

Once filled, 3d energy level is lower than 4s .

Question 19

What is different about the electron configuration of Cr?

Answer 19

4s1 3d5
it is more stable to have a half full d-subshell than a full s-subshell.

Question 20

What is different about the electron configuration of Cu?

Answer 20

4s1 3d10
it is more stable to have a full d-subshell than a full s-subshell.

Question 21

What is ionic bonding?

Answer 21

The electrostatic attraction between positive and negative ions.

Question 22

What is the structure of ionic compunds?

Answer 22

Giant ionic lattice

Question 23

Properties of ionic compounds:

Answer 23

• Solid at room temp
• High melting and boiling points
• Dissolve in polar solvents
• Conducts electricity when molten or dissolved.

Question 24

What is covalent bonding?

Answer 24

The strong electrostatic attraction between a shared pair of electrons and the nuclei of bonded atoms.

Question 25

What are the 3 ways atoms can be bonded covalently?

Answer 25

small molecule, giant covalent structure, charged polyatomic ion.

Question 26

What does a localised attraction mean?

Answer 26

Attraction acts solely between the shared pair of electrons and the nuclei of the two bonded atoms.

Question 27

What is a molecule?

Answer 27

The smallest part of a covalent compound that can exist whilst retaining the chemical properties of the compound.

Question 28

When does expansion of the ocet occur?

Answer 28

When an atom is able to have more than 8 valence electrons. e.g. in SF6, all 6 S atoms pair to form 6 covalent bonds.

Question 29

What are multiple covalent bonds?

Answer 29

Two atoms share more than one pair of electrons

Question 30

What are dative covalent bonds?

Answer 30

The shared pair of electrons has been supplied by only one of the bonding atoms. The shared pair was originally a lone pair.

Question 31

What is average bond enthalpy?

Answer 31

A measure of covalent bond strength.

Question 32

What is electron-pair repulsion theory?

Answer 32

Electron pairs surrounding a central atom determine the shape of the molecule or ion. Arrangement of electron pairs minimises repulsion, holding the bonded atoms in a definite shape.

Question 33

Why do lone pairs reduce the bond angle?

Answer 33

They repel more strongly.

Question 34

3 BP, 0LP name and angle

Answer 34

Trigonal planar, 120

Question 35

4 BP, 0LP name and angle

Answer 35

Tetrahedral, 109.5

Question 36

6 BP, 0LP name and angle

Answer 36

Octahedral, 90

Question 37

2 BP, 0LP name and angle

Answer 37

Linear, 180

Question 38

3 BP, 1LP name and angle

Answer 38

Pyramidal, 107

Question 39

2 BP, 2LP name and angle

Answer 39

Non-linear, 104.5

Question 40

What is electronegativity?

Answer 40

The ability of an atom to attract the bonding electrons in a covalent bond.

Question 41

What is the range of electronegativity difference to be classified as a polar covalent bond?

Answer 41

0 - 1.8

Question 42

When do non-polar covalent bonds occur?

Answer 42

Between two identical atoms as the electrons are shared equally. Or if the atoms have similar electro-negativity (C-H)

Question 43

When do polar covalent bonds occur?

Answer 43

Atoms bonded together are different, one of the atoms attracts the electrons more, causing a permanent dipole.

Question 44

When is a molecule symmetrical?

Answer 44

- No lone pairs, only bonding pairs - All the bonds are the same - Dipoles cancel out so the molecule is non-polar.

Question 45

What are inter molecular forces?

Answer 45

Weak interactions between dipoles of different molecules.

Question 46

What are the 3 main categories of inter-molecular forces?

Answer 46

- Induced dipole - dipole interactions / London forces. - Permanent dipole - dipole interactions. - Hydrogen bonding.

Question 47

How do London forces form?

Answer 47

1. Movement of electrons produces a changing dipole. 2. Instantaneous dipole forms and induces a dipole on a neighbouring molecule. 3. Induced dipoles attract one another.

Question 48

How can you increase the strength of London forces?

Answer 48

More electrons in each molecule

Question 49

When do hydrogen bonds form?

Answer 49

A NOF atom (electro-negative) bonded to a hydrogen atom (electro-positive)

Question 50

What are 3 anomalous properties of water?

Answer 50

- Solid is less dense than liquid - Relatively high melting and boiling points - Relatively high surface tension and viscosity.