Atomic orbitals, electronic configurations and the periodic table Flashcards
How do
Electrons behave in an atom
Like stationary waves, vibrate in time but do not move in space
Different sizes and shapes of these are possible around the nucleus
(orbitals!)
What are the
Fixed amounts of energy electrons have in atoms
Called
Quanta
Four quantum numbers that describe where the electron in an atom is
- Principle quantum number (n)
- Angularmomentum qn (l)
- Magnetic qn (ml)
- Spin quantum number (ms)
Principle quantum number n
Inidcates energy level of electron
Angular momentum quantum number L
Determines shape of subshell, has values from 0 to n-1
Magnetic quantum number ml
determines orientation of the orbital, has values between l-1 and l+1
Spin magnetic quantum number ms
Determines direction of spin, can be +1/2 or -1/2
Electrons within atoms are arranged according to
- Aufbau Principle
- Hunds Rule
- -The pauli exclusion principle
Aufbau Principle
Electrons fill orbitals of increasing energy
Aufbau means building up in german
Hunds rule
When degenerate orbitals are available, electrons fill singly, keeping spins paralell before doubling up
The pauli exclusion principle
No two electrons in one atom can have the same 4 quantum numbers, therefore orbitals can hold only 2 electrons with opposite spins
Degenerate
Orbitals that have the same energy
Ionisation energy
The energy required to remove on mole of electrons from one mole of the gaseous atom
E(g)> E+(g) + e-
The highest points on IE graph are the noble gases(hard) and lowest are alkali metals(easier)
