Atoms, molecules & the periodic table Flashcards
What is the “Atomic number”?
of protons
What is the “Mass number”?
of nucleons (protons + neutrons)
What is the “Principal quantum number”?
size of the orbital (n=1,2,3,4,..)
What is the “Angular momentum number”?
shape of the orbital (1=0,1,2,3..)
What is the “Magnetic quantum number”?
spatial orientation (ml=-1,0,1)
What is the “Electron spin quantum number”?
spin (-1/2, +1/2)
What is the “Aufubau Rule”?
Electrons fill the lowest available energy levels before filling higher levels
What is the “Pauli Exclusion Principle”?
Orbitals can contain a maximum of two electrons, which must be of opposite spin
What is the “Hund’s Rule”?
Electrons enter the orbitals of equal energy one-at-a-time to maximize degeneracy
What is the “Madelung’s Rule”?
Orbitals fill the electrons in the order of increasing n+1 value
What is the “Relative atomic mass”?
Average of naturally-occurring atomic mass values for samples of elements
What is “Atomic Radius”?
Increases down a group (more shells) and decreases from left to right across a period (growing effective nuclear charge)
What is “Ionization Energy”?
- Minimum energy required to remove an electron from a gaseous atom or
ion when the atom or ion is in its ground state - First ionization energy generally increases from left to right across a
period and up a group (smaller atoms are more difficult to ionize) - ALWAYS positive; it always takes energy (positive)
What is “Electron Affinity”?
- Energy change that occurs when electron is added to a gaseous atom
1. Energy is released upon electron uptake - Chlorine has the largest EA -> releases the greatest amount of E
- Absolute value of EA has similar trend as the IE (very small atoms (O or F) are exceptions due to high electron density
