Atomic Orbitals Flashcards
Probability and Electrons
Electrons can be find at any point at any given location around the nucleus. The probability model tells us that they can be anywhere, but they are much more likely to be found in specific regions around the nucleus called atomic orbitals.
Energy Levels (1, 8, 18)
Energy levels (valence shells) are divided into sub-shells and atomic orbitals. A single atomic orbital contains MAX 2 electrons. This means in first shell, there is orbital (2 electrons), second there is 4 orbitals (8 electrons), third there 9 orbitals (18 electrons).
S, P, D subshells
S orbital is spherical, but p, d and f is less intuitive. There are 3 shapes for p orbitals (with two shapes), 5 shapes for d orbitals (with 3 or 4 shapes). F sub shells are just completely fucked. Only need to know configurations for first 36 elements anyway.
Shapes
S is circle (one type). P has two thingies, 3 types. D has 5 types, 3 or 4 thingies. Only need to know first 36 so no F orbitals.
Aufbau Principle
In the ground state of an atom, electrons will fill lowest energy atomic orbitals first. Order goes 1s, 2s, 2p, 3s, 3p, 3d,4s,4d,4f. So the number indicates what shell it is in. Eg 4s is in 4th shell of 32 electrons.
Initial Filling order
1s, 2s, 3x2p, 3s, 3x3p
For electron configurations above 18
When we get to more than 18 electrons, the picture is more complicated because 3d and 4s orbitals are very close in energy. Therefore, 4s fills before 3d!!! Same thing with 4s before 5d.
Order goes 4s, 3d, 4p, 5s, 4d, 5p, 6s
Transition metal
A transition metal is an element whose atom has a partially filled d-subshell which can give rise to cations with an incomplete d-subshell.
Exceptions to the Aufbau Principle
The Aufbau principle is a guide to electron configurations. Chromium and copper are exceptions to the Aufbau principle. Chromium has an electron configuration of [Ar] 4s1 3d5 (partially filled), whereas Cu has [Ar] 4s1 3d10 (fully filled). This occurs because the actual configuration is more stable.
Transition metal ions
Like all metalas, transition metals lose electrons to form cations. Cations are formed by losing valence electrons. For transitin metals with atomic number less than 36, this means they lose their 4s electrons first.
