Wavefunctions of atomic orbitals

Table 2.1.4. The total wavefunctions of atomic orbitals with n = 1-4...

So why is phase important Well, in a moment we will see that, just as atoms add together to give molecules, we can add together the wavefunctions of atomic orbitals to give molecular orbitals, which tell us where electrons are, and how much energy they have, in molecules. 

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