Surface tension gases. The pressure inside an ideal (one surface) soap bubble can be derived from thermodynamic free energy considerations. At constant temperature and particle number, , the differential Helmholtz energy is given by where is the difference in pressure inside and outside of the bubble, and is the surface tension. In equilibrium, , and so, For a spherical bubble, the volume and surface area are given simply by and Substituting these relations into the previous expression, we find which is equivalent to the Young–Laplace equation when . For real soap bubbles, the pressure is doubled due to the presence of two
Solid surface the cured joint is machined flat. The same method is used to build up edge thickness, which can be profiled using tools and techniques similar to those used to work hardwoods. A major appeal of solid surface is its impermeability. Solid surface sinks can be joined to the countertop surface with no gaps, which eliminates areas for water to collect and bacteria to grow. Integral backsplashes can also be created that follow the contours of the wall “seamlessly” and without gaps. Should the material become scratched or broken, solid surface can, in most cases, be repaired quickly by a certified