Atomic Structure Flashcards
What is the brief history of atomic models?
Dalton: Atom = indivisible solid sphere. Thomson: ‘Plum pudding’ model. Rutherford: Dense positive nucleus. Bohr: Electrons in fixed orbits.
What are subatomic particles and their charges?
Proton: +1 charge, mass = 1 amu. Electron: -1 charge, mass ≈ 1/1836 amu. Neutron: 0 charge, mass ≈ 1 amu.
How do subatomic particles behave in an electric field?
Protons deflect to negative plate. Electrons deflect to positive plate (more sharply). Neutrons show no deflection.
What are atomic number and mass number?
Atomic number (Z): Number of protons. Mass number (A): Protons + Neutrons.
What is atomic and ionic radius? What are the trends?
Atomic radius: Half distance between nuclei. ↓ down group (increases), → across period (decreases). Ionic radius: Cations smaller, anions larger than parent atoms.
What are the four quantum numbers?
n: Principal (energy level), l: Azimuthal (shape), m: Magnetic (orientation), s: Spin (+1/2 or -1/2).
What are the basic rules for electronic configuration?
Aufbau: Fill lower orbitals first. Pauli Exclusion: No two electrons same quantum numbers. Hund’s Rule: Fill singly before pairing.
What is the (n + l) rule?
Orbital with lower (n + l) filled first. If same (n + l), lower n filled first.
What are the shapes of s, p, d orbitals?
s: Spherical, p: Dumbbell, d: Cloverleaf-shaped.
What is ionization energy?
Energy to remove an electron from gaseous atom. → across period (increases), ↓ down group (decreases).
What is mass spectrometry?
Measures mass-to-charge (m/z) ratio of ions. Steps: Ionization → Acceleration → Deflection → Detection.
What is doping in semiconductors?
Doping: Adding impurities to silicon. n-type: Add extra electrons (P, As). p-type: Add fewer electrons (B, Al).
