Chapter 5 - Electrons and Bonding Flashcards

Electron structure, Ionic bonding and structure and Covalent bonding.

1
Q

Shells are regarded as what?

A

Energy levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens to energy as the shell number increases?

A

Energy increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the shell number referred to as?

A

Principal quantum number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are shells made up of?

A

Atomic orbitals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How many electrons can be held in an orbital?

A

One or two, no more.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What can an electron be thought of as?

A

A negative-charge cloud with the shape of the orbital, called an electron cloud.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the different orbitals?

A

S-orbitals
P-orbitals
D-orbitals
F-orbitals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How many orbitals does each type contain?

A

S - one
P - three
D - five
F - seven

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How many electrons can be held in each orbital type?

A

S - two
P - six
D - ten
F - fourteen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the shape of an s-orbital?

A

Spherical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the shape of a p-orbital?

A

Dumbbell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the rules of orbital fillings?

A

Orbitals fill in order of increasing energy.
Electrons pair with opposite spins.
Orbitals with the same energy are occupied singly first.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Explain the rule of orbitals filling in order of increasing energy

A

1s is filled first.
For n=2 shell, filling order is: 2s, 2p
For n=3 shell, filling order is 3s, 3p, 3d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where does this rule cause confusion?

A

The 3d sub-shell has higher energy than the 4s.

So the 4s fills before the 3d.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain the rule of electrons pair with opposite spins

A

Electrons are negatively charged and repel one another.
Electrons can have spin up or spin down.
If electrons have opposite spin, the charge repulsion is counteracted enough for both to be in the orbital.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Explain the rule of orbitals with the same energy are occupied singly first

A

Within a sub shell, the orbitals have the same energy. One electron occupies each orbital before pairing begins. This prevents repulsion until no unoccupied orbitals remain.

17
Q

How can electron configuration be shortened?

A

1s2 can be expressed as [He].
1s2 2s2 2p6 can be expressed as [Ne].
1s2 2s2 2p6 3s2 3p6 can be expressed as [Ar].

18
Q

What happens in terms of energy sub-shells when forming ions?

A

The highest energy sub-shells lose or gain electrons.

19
Q

What is ionic bonding?

A

The electrostatic attraction between positive and negative ions.

20
Q

What is the result of ions attracting oppositely charged ions in all directions?

A

Giant ionic lattice

21
Q

How are the melting and boiling points of ionic compounds explained?

A

High temperatures are required to provide the energy sufficient to overcome the strong electrostatic attraction between the ions.

22
Q

What happens to the melting points for giant ionic lattices, when ionic charge increases?

A

Melting point increases as there is a stronger attraction between ions.

23
Q

Are ionic compounds soluble?

A

They dissolve in polar solvents such as water.

24
Q

What does solubility require?

A

The ionic lattice must be broken down.

Water molecules must attract and surround the ions.

25
Q

What does solubility (of ionic compounds) depend on?

A

The relative strengths of the attractions within the giant ionic lattice and the attractions between ions and water molecules.

26
Q

When can ionic compounds conduct electricity?

A

Not in the solid state.

When molten or dissolved in water.

27
Q

Why can’t ionic compounds conduct electricity when solid?

A

The ions are in a fixed position.

There are no mobile charge carriers.

28
Q

Why can ionic compounds conduct electricity when molten or dissolved in water?

A

The solid ionic lattice breaks down.

The ions are now free to move as mobile charge carriers.

29
Q

Summarise the properties of most ionic compounds

A

High melting and boiling points.
Tend to dissolve in polar solvents such as water.
Conduct electricity only in the liquid state or in aqueous solution.

30
Q

What is covalent bonding?

A

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

31
Q

What actually is a covalent bond?

A

The overlap of atomic orbitals, each containing one electron, to give a shared pair of electrons.

32
Q

How does covalent bonding differ to ionic bonding?

A

The attraction is localised, acting only on the shared pair of electrons and the two nuclei of the bonded atoms.

33
Q

How can covalent bonding be displayed?

A

With dot and cross diagrams.

34
Q

What is a multiple covalent bond?

A

Two atoms share more than one pair of electrons.

35
Q

What is a double bond?

A

The electrostatic attraction is between two shared pairs of electrons, and the nuclei of the bonding atoms.

36
Q

What is a triple bond?

A

The electrostatic attraction is between three shared pairs of electrons, and the nuclei of the bonding atoms.

37
Q

What is a dative covalent bond?

A

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

38
Q

Give an example of a dative covalent bond

A

An ammonia molecule donates its lone pair of electrons to an H+ ion.
Forming an ammonium ion.

39
Q

What is average bond enthalpy?

A

A measurement of covalent bond strength.

Larger value = stronger bond