5. ATOMIC AND ELECTRONIC STRUCTURE (PART 3) Flashcards
1
Q
- Provide names for the following labels?
A
- Element
- Total Electrons
- Box Orbital Diagram
- Electron Configuration
- Number of Electrons
2
Q
- What does Hund’s Rule state?
A
- we should maximise the number of unpaired spin-up electrons
3
Q
- What happens when we pair up electrons in the same orbital?
A
- we force them to share the same space
- both electrons are negative
- both electrons have the same charge
- these two electrons repel each other
- the increase in repulsion causes an increase in the energy of the atom
- the atom is less stable
NB: this is why we keep electrons unpaired
4
Q
- How and why do we keep electrons unpaired?
A
- we keep them unpaired by placing them in adjacent orbitals
- they have a lower repulsive energy when they are unpaired
- there is no electromagnetic resistance
- the orbital is much more stable
5
Q
- Do we place the unpaired electrons as spin-up or spin-down electrons?
WHY?
A
- spin up electrons
- they have a lower energy as they are working in the same direction of the magnetic field
- the atom is more stable
6
Q
- Which of these Carbon atoms is the most stable?
A
- Option D
7
Q
- What does a violation of Hund’s Rule lead to?
A
- it leads to excited electronic states
- these have a higher energy than the lowest ground state
8
Q
- Provide names for the following labels?
A
- Ground state
(the lowest energy state) - Excited State
(higher energy) - Excited State
(higher energy) - Excited State
(higher energy)
9
Q
- What is Pauli’s Exclusion Principle?
A
- no two electrons in a given atom can have the same set of 4 quantum numbers
- at least one of the quantum numbers has to be different
- the quantum numbers are: n, L, mL, mS
10
Q
- Which of these are the two best examples of Pauli’s Exclusion Principle?
A
B and C
11
Q
- What type of Electronic Configuration is this?
A
Full Electronic Configurations
12
Q
- What type of Electronic Configuration this is?
A
Noble Gas Electron Configurations
13
Q
- What type of Electronic Configuration is this?
A
Condensed Electronic Configurations
14
Q
- Provide names for the following labels?
A
- Full Electronic Configuration
- Condensed Electronic Configuration
- Box Orbital Diagram
15
Q
- What kind of Electronic Configuration is this?
A
- it is an Anomalous Electronic Configuration
16
Q
- What happens in an Anomalous Electron Configuration?
A
- one electron is promoted from the 4s to the 3d sub shell
- this is to achieve a d5 (half full d sub shell) or a d 10 (full d sub shell) configuration
17
Q
- Why is a d5 or a d10 sub shell desirable?
A
- they have a special degree of stability
18
Q
- Can you change a d3 or a d8 sub shell to a d5 or a d10 sub shell?
A
- NO
- you can only change a d4 or a d9 sub shell
19
Q
- Elements in which other groups will have anomalous electronic configurations?
A
- Group 6
- Group 11
20
Q
- Electrons from which orbital are likely to leave first when there is a transfer of electrons (ionic/covalent bonding)?
A
- electrons from the s orbital
- this is the outermost electron configuration
- these electrons are found in the outermost shell of the atom
21
Q
- What is another name for the electrons found in the outermost shell, and what do they do?
A
- they are called Valence electrons
- they are exchanged between other atoms
22
Q
- What is shielding?
A
- it is when we cannot see the nucleus of the atom as something is blocking us from seeing it
- an electron cloud or a higher density of electrons in the shells is what causes this shielding
23
Q
- What is the value and the symbol of the valence electrons of Group 1 (Alkali Metal) elements?
A
- s1
- they have an extra electron to freely give away to reach an octet (most stable state)
24
Q
- What is the value and the symbol of the valence electrons of Group 7 (halogens) elements?
A
- p6
- they are seeking an extra electron to reach an octet (most stable state)
25
Q
- What is atomic radius?
A
- the distance from the centre of the atom to its circumference
- it can also be seen to be the size of the atom
26
Q
- How does the atomic radius react with regard to groups and periods?
A
- it increases as we move down the group
- it decreases as we move right along the period
27
Q
- Why does the atomic radius increase as we move down the group?
A
- this is due to the addition of extra shells as we move down the group
- the extra shells have an increasing Principle Quantum Number (n)
- this makes them larger in size
28
Q
- Why does the atomic radius decrease as you go along the period?
A
- electrons are being placed in the same shell as we move along the period
- these shells are still at the same distance from the nucleus as they were before the addition of the other electrons
- the nuclear charge increases by one unit each time we move to the right
- the increasing nuclear (positive) charge attracts the electrons in the shells
- this pulls the shells closer to the nucleus
- this decreases the size of the atom
29
Q
- What is the Ionisation energy?
A
- the energy required to remove one electron from a neutral atom
- it is the energy we have to use up in order to remove the electron from the attractive force of the nucleus
30
Q
- Which law is proven through the fact that electrons are attracted to the nucleus?
A
- Coulomb’s law
31
Q
- What is the formula to work out the ionisation energy?
A
32
Q
- What does Q1 represent?
A
- the effective nuclear charge
(the number of protons-the number of intermediate electrons)
33
Q
- What are intermediate electrons?
A
- electrons that shield the nucleus
- this ensures that the valence electron does not feel the full positive charge
34
Q
- What does Q2 represent?
A
- it is equal to the value of one electron
(Q2 = -1)
35
Q
- What happens the atomic number increases?
A
- Q1 increases
- the energy of attraction to the electron also increases
- this makes it much more difficult to separate an electron from it’s attractive force to the nucleus
36
Q
- What does R represent?
A
- the distance of the electron from the nucleus
37
Q
- What happens when R increases?
A
- the energy of attraction decreases
38
Q
- What happens when the number of atomic shells increases?
A
- R increases
- energy of attraction decreases
39
Q
- What has exactly the opposite trend than the atomic radius?
A
- the ionisation energy
40
Q
- Read through the summary.
Does everything make sense?
A
- yes