EL 3 & 4 Flashcards
What are shells made up of?
- Sub-shells
- Orbitals
Which shells have greater energy levels?
Shells further from the nucleus
How many electrons can orbitals hold?
2
What are the 4 types of sub-shells in order?
S p d f
How many orbitals does each sub shell have?
S - 1
P - 3
D - 5
F - 7
What are the maximum number of electrons in each sub-shell?
S - 2
P - 6
D - 10
F - 14
What sub-shells are in the first shell?
1s
What sub-shells are in the second shell?
2s 2p
What sub-shells are in the third shell?
3s 3p 3d
What sub-shells are in the fourth shell?
4s 4p 4d 4f
What are orbitals?
A region of space which has a 95% chance of holding 2 electrons
What happens in orbitals?
Spin pairing - electrons in orbitals spin in opposite directions
What are the 2 main shapes of orbitals?
S orbital
P orbital
How do electrons fill orbitals?
Singly before they start pairing up
How is the periodic table organised?
By increasing atomic number
How do you write the electronic configuration of Ca (Z20)?
1s2 2s2 2p6 3s2 3p6 4S2
How do you work out the configuration of an ion up to Ca?
- Write down electronic structure
- Add or remove electrons to or from the highest-energy occupied shell
How do you work out the configuration of an ion in d-block?
Fill the 4s sub-shell before the 3d sub-shell
Why does melting/boiling point increase across period 1 to period 3?
- giant metallic bonding is strong
- Each group contributes more electrons to the sea of delocalised electrons
Why does melting/boiling point decrease across period 5 to period 8?
- simple molecular bonding (molecules are held together by weak intermolecular bonds)
Why does reactivity increase down a group?
- Number of shells increases
- Shielding increases
- Atomic radius increases
- First ionisation energy decreases
What is first ionisation energy?
The amount of energy required to remove the outer electron
What is periodicity?
Trends : a regular variation in properties of element with atomic number and position in the periodic table
