2.3 The wave-function and electron cloud 2.3.1 The wave-functions of hydrogen-like ions 之3 Zr 1 Ψ2= (2- 2a0 41 2π4 ao r=2ao 2345 r=4ao Fig.(left)The y-r and y2-r diagram of the 1s state of the hydrogen atom.(right)The y-r of the 2s state.2.3 The wave-function and electron cloud 2.3.1 The wave-functions of hydrogen-like ions 0 3 1 3 0 Zr a s Z e a ψ π − = 0 3 2 2 3 0 0 1 (2 ) 4 2 Zr a s Z Zr e a a ψ π − = − Fig. (left) The ψ-r and ψ2-r diagram of the 1s state of the hydrogen atom. (right) The ψ-r of the 2s state . r=2a0 r=4a0