Lesson 1: The Periodic Table and Orbitals Flashcards
1
Q
Subshells and the Periodic Table
Blocks
A
- s-block: groups 1 & 2 (+ helium).
- p-block: groups 13-18.
- d-block: transition metals.
- f-block: lanthanides & actinides.
2
Q
Electron Configuration
Description
A
- Describes how electrons are distributed within atomic orbitals.
- Follows a standard notation in which all electron-containing subshells are placed in sequence.
3
Q
Electron Configuration
Components
A
- Letter: the subshell electrons are occupying.
- Superscript number: amount of electrons within that subshell.
- Large number: represents the energy level (shell).
Eg. Sodium = 1s² 2s² 2p⁶ 3s¹
4
Q
Electron Configuration
Ions
A
- Calcium forms 2+ ions.
- It has lost 2 electrons, so there are less overall.
- Original: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
- Ion: 1s² 2s² 2p⁶ 3s² 3p⁶
5
Q
Subshells and the Periodic Table
Subshells
Number of Electrons
A
- s holds up to 2.
- p holds up to 6.
- d holds up to 10.
6
Q
Electron Configuration
Aufbau Principle
A
Electrons fill the orbital with the lowest available energy state first.
7
Q
Electron Configuration
Energy Levels
Number of Electrons
A
- 1st shell: 2 electrons (s).
- 2nd shell: 8 electrons (s, p).
- 3rd shell: 18 electrons (s, p, d).
- 4th shell: 32 electrons (s, p, d, f).
8
Q
Orbitals
Subshells
Number of Orbitals
A
- s subshell: 1 orbital.
- p subshell: 3 orbitals.
- d subshell: 5 orbitals.
- f subshell: 7 orbitals.
9
Q
Orbitals
Description
A
- Region around the nucleus where the probability of finding the electron is greatest.
- Holds 0, 1 or 2 electrons.
- Arrows in orbital diagrams represent electrons spinning in pairs.
10
Q
Orbitals
Filling Orbitals
Hund’s Rule
A
- Start with the lowest energy orbital (1s).
- In each orbital, electrons are spread out to maximise the number of unpaired electrons.
- Arrows are shown pointing up (and down for opposite spins).
