Electron Configuration & Orbital rules Flashcards
To understand how electron configuration works and how the orbital rules apply
What are the four types of electron sublevels?
s, p, d, and f.
How many electrons can each sublevel hold?
s (2), p (6), d (10), f (14).
What principle states that electrons fill the lowest energy orbitals first before moving to higher ones.
the Aufbau Principle?
What rule states that electrons occupy empty orbitals one at a time before doubling up in the same sublevel.
Hund’s Rule
How do you write the electron configuration of an element?
By following the order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, etc.
Q: What is the electron configuration of sodium (Na, Z=11)?
1s² 2s² 2p⁶ 3s¹.
Q: What are the electron configuration exceptions for Cr and Cu?
A: Cr: [Ar] 4s¹ 3d⁵
Cu: [Ar] 4s¹ 3d¹⁰ (due to extra stability of half/full d-subshells).
Q: What is the relationship between electron configuration and the periodic table?
The electron configuration determines an element’s position in the periodic table, with periods corresponding to energy levels and groups representing the number of valence electrons.
What are valence electrons?
Valence electrons are the electrons in the outermost shell of an atom, which are involved in chemical bonding.
How does the electron configuration explain the reactivity of elements?
Elements are most reactive when they have incomplete outer shells (e.g., alkali metals with one electron in their outer shell or halogens with seven).
Q: What is the significance of the noble gas configuration?
Noble gases have full electron shells, making them chemically stable and unreactive, which is why other elements tend to gain or lose electrons to achieve a noble gas configuration.
What is the electron configuration of an ion?
A: The electron configuration of an ion is determined by adding or removing electrons to achieve a stable electron arrangement typically resembling the nearest noble gas.
For example, Na⁺ has the same configuration as Ne: 1s² 2s² 2p⁶.
