Quantum Numbers and Electron configuration Flashcards
Q: What is quantum theory?
A: Quantum theory explains the behaviour of electrons, describing them as both particles and waves (wave-particle duality).
Q: What is wave-particle duality?
A: Electrons have properties of both particles (mass, charge) and waves (quantized energy levels).
Q: What does it mean that electrons have quantised energy levels?
A: Electrons absorb and emit energy in discrete units rather than in a continuous amount.
Q: Why do we need quantum numbers?
A: Quantum numbers describe the probable location and behaviour of electrons in an atom.
Q: What does the principal quantum number (n) describe?
A: It describes the size and energy level of an orbital.
Q: How do increasing values of (n) affect orbitals?
A: As n increases, the orbital gets larger and the electron has higher energy.
Q: What are some examples of orbitals for different values of (n)?
A:
n = 1 → 1s orbital
n = 2 → 2s, 2p orbitals
n = 3 → 3s, 3p, 3d orbitals
Q: What does the azimuthal quantum number (l) describe?
A: It defines the shape of the orbital.
Q: What values can (l) take?
A:
l = 0 (s orbital, spherical shape)
l = 1 (p orbital, dumbbell shape)
l = 2 (d orbital, four-leaf clover shape)
Q: How does (l) depend on (n)?
A: l ranges from 0 to (n-1). Example: If n = 3, possible values of l are 0, 1, and 2.
Q: What does the magnetic quantum number (ml) describe?
A: It describes the orientation of the orbital in space.
Q: How do the values of ml depend on l?
A: ml can range from -l to +l.
Q: How many orientations do different orbitals have?
A:
s orbital: 1 orientation (ml = 0)
p orbital: 3 orientations (ml = -1, 0, +1)
d orbital: 5 orientations (ml = -2, -1, 0, +1, +2)
Q: What does the spin quantum number (ms) describe?
A: It describes the direction of electron spin.
Q: What are the possible values of (ms)?
A:
+1/2 (spin-up)
-1/2 (spin-down)
Q: What is the Pauli Exclusion Principle?
A: No two electrons in an atom can have the same set of quantum numbers.
Q: How many electrons can occupy an orbital?
A: Each orbital can hold a maximum of two electrons, with opposite spins.
Q: What are orbitals?
Q: What are orbitals?
A: Orbitals are regions of space around the nucleus where electrons are most likely to be found.
Q: What do orbital shapes represent?
A: They represent a probability distribution of where electrons are likely to be found.
Q: What are the three main types of orbitals relevant in this course?
A:
s orbital (spherical shape)
p orbital (dumbbell shape)
d orbital (four-leaf clover shape)
Q: How are orbitals arranged in the periodic table?
A: Elements in higher periods have electrons in larger orbitals with higher energy levels.
Q: How does electron spin affect filling orbitals?
A: Each orbital must contain one spin-up electron before any spin-down electrons are added.
