# Why is sand/glass polar? How does lattice structure change polarity?

The molecular geometry of sand is linear. Dipole moment is thus cancelled.

But we all know from the meniscus water makes with glass that the dipole-dipole/H-O attraction between sand and water is stronger than the hydrogen bond between water molecule. maybe I am wrong

My guess is either that electron lone pair makes it polar or the lattice structure does.

I'm not sure where you get the idea that glass is linear. What makes a glass is the lack of long range ordering, though in fused silica, the approximate tetrahedral structure of $\ce{SiO4}$ is maintained (this is a 2D section, the fourth oxygens are not shown):
$$\ce{Si-OH <=> Si-O- + H+}$$