Electron Configuration
Electron configuration for O?
1s² 2s² 2p⁴
Differentiate between Ions and isotopes
Ion: charged atom (gains/loses e⁻); Isotope: same element, different neutrons
Who proposed the planetary model?
Niels Bohr
Valence electrons in Carbon
4
What is the maximum number of electrons in a p subshell?
6
Electron configuration for Na?
1s² 2s² 2p⁶ 3s¹
Protons, neutrons, electrons in ²³Na⁺?
P: 11, N: 12, E: 10
What does orbit represent
Specific energy level where electron resides
Lewis dot for H₂?
H–H (single bond)
Shape of an s orbital?
Spherical (Sphere)
Which element has 1s² 2s² 2p⁶ 3s¹?
Sodium (Na)
Define isotope and example
Same protons, different neutrons; e.g., ¹²C & ¹³C
Energy change when electron jumps up?
Electron absorbs energy (higher orbit)
Lewis structure for H₂O?
O in center with 2 H bonded + 2 lone pairs on O
Orbitals in d subshell?
5
Shorthand config for Cl?
[Ne] 3s² 3p⁵
How does ion charge relate to electrons?
Positive ion: loses e⁻; Negative ion: gains e⁻
Orbit radius vs energy
Larger orbit → higher energy
Lone pairs in NH₃?
1 Lone pair on N
Max electrons per orbital
2
Hund’s Rule?
Fill degenerate orbitals singly before pairing electrons
Calculate average atomic mass
Σ (isotope mass × % abundance)
Why no electrons between orbits
Electrons can only exist in quantized energy levels
Lewis structure for CO₂?
O=C=O (double bonds, no lone pairs on C, 2 lone pairs on each O)
Name 4 orbital types
s, p, d, f