And what we ultimately form after step one is we form a tetrahedral intermediate. So in this particular case, if we examine this bond here, we see that we have SP two hybridization. And what that means is this is going to be a planar molecule and that gives this molecule stability. But as soon as this attack takes place, we form a tetrahedral intermediate. And on top of that we're going to have a negative charge on this oxygen and this tetrahedral intermediate. Because of that negative charge, and because this molecule is no longer planar, it's not going to be a stable.