Liquid helium is a superfluid with zero viscosity, which flows without losing kinetic energy. - When stirred, superfluid forms vortices that rotate indefinitely. The viscosity of superfluid helium can be understood in the classical two-fluid model, where only the normal fluid contributes to the viscous response. The abrupt drop in the mobility of electrons leads to a change in the solvation structure: the electron becomes localized and forms a sizeable spherical cavity (''bubble'') in the medium. However, it is hard to imagine that the positively charged nuclei are dissolved in the negatively charged electrons. From the viewpoint of orbital symmetry, the following atomic orbital shape change is depicted in this paper. As shown in Fig. , assuming that the shape of helium in gas is elliptic, whereas in the interval 4.2-5.2 K, the shape is spherical, we get n=2 for gas and n=1 for liquid. After that, the shape of helium in liquid changes as the temperature decreases. In addition, the mobility of helium in liquid is enhanced as the temperature decreases. Hence, A values become negative. In H2 and D2, A decrease is also observed as the temperature decreases. As shown in Fig. , for H2, A=1.48 in the region of Tc, but A=0.79 in the area of M.P. As for D2, the decrement of A is decreased considerably to 0.2. It implies that the mass of nuclei may relieve the particularity. On the other hand, comparing the Y•T~T curves of He-4 (Fig. ) and H2, it is observed that if extrapolating the temperature to 0 K, the H2 curve might exhibit a similar shape to He. That is to say, increasing entropy near 0 K is possibly expected for all the gases.