1.2 the Hydrogen atom

Energy Levels

• they are discrete and they contain electrons.
• n=1 is the ground state, the lowest energy level an electron can be in
• electrons can be excited between energy levels. to excite, to above the ground state. this happens if they absorb a photon that has the exact energy difference between the two energy levels.
• electrons can release a photon and move down an energy level.

s-Orbitals

• It is spherically symmetric around the atoms nucleus.
• As energy levels increase, the orbitals get bigger.
• It is a region of space in which s electrons live.
• they can only store up to 2 electrons in a pair.
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p-Orbitals

• from the second level, there are p-Orbitals available.
• they can store up to 6 electrons, in 3 pairs.
• you can have 3 equivalent p-orbitals; px, py and pz.
• they contain 2 lobes. At higher energy levels, the lobes become more elongated.
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d-Orbitals

• from the third energy level, electrons can be stored in d-orbitals.
• they can hold 10 electrons in 5 electron pairs.
• there are 5 different d orbitals; 3dxy, 3dxz, 3dyz, 3dx2-y2 and 3dz2
• In order to see how they are named, we need to look at them in two groups:
• The first group contains the 3dxy, 3dxz and 3dyz orbitals. The names tell you that these orbitals lie in the x-y plane, the x-z plane, and the y-z plane, respectively. Each orbital has four lobes, and each of the lobes is pointing between two of the axes, not along them.
• The second group contains the 3dx² - y² and 3dz² orbitals. Their lobes point along the various axes. The 3dx² - y² orbital looks exactly like the first group, except that that the lobes are pointing along the x and y axes, not between them.The 3dz² looks like a p orbital wearing a doughnut around its waist.
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Simplest Schrodinger equation: