AsO4 polarity?

[HoneyWalnutShrimp]

Why is AsO4 non polar? Even if the double bonded oxygen sort of cancels out some of the dipole moment vector, dont the other three having full on negative charges still overpower the double bond?

[206363692]

AsO4 3− is nonpolar bc of its symmetric tetrahedral geometry, which causes the dipole moments of its bonds to cancel out.
The central atom is surrounded by four oxygen atoms in a tetrahedral arrangement, and each As--O bond is polar because oxygen is more electronegative than arsenic, creating a dipole moment. The overall ion has a 3− charge, and while the ion's overall charge increases the polarity of individual bonds, the overall polarity is determined by the symmetry of the ion. Because the geometry is tetrahedral, the bond dipoles point in directions that are symmetric around the central atom, As. The result is the vector sum of the dipole moments cancelling out completely, making the molecule nonpolar.