What is the moleclar shape of SiBr4?

Answer 1

Tetrahedral, just like methane.

The 'Si' (Silicon) is immediately below Carbon in Group 4. So it behaves very similarly to carbon . Silicon , like carbon has four outer most electrons in its outer energy shell , so it will make four bonds. One each to each of the Bromines (Br).

Silicon like carbon has the ability to catenate, that is form chains by bonding to itself. This feature is not as strong in silicon. The crystalline structure of sand ( silicon dioxide) is such that silicon bonds to itself and to oxygen.