To determine which molecule has a stable configuration, we need to consider the stability of the atoms involved typically represented by the octet rule for main group elements.
-
SiO5 - Silicon typically forms bonds that allow it to have 4 bonds (not stable with 5 oxygens).
-
MgBr2 - Magnesium can give up 2 electrons to form Mg2+, and each bromine atom can gain 1 electron to form Br-. This configuration is stable.
-
KCl2 - Potassium typically forms K+, while chlorine tends to form Cl-. KCl is stable, but KCl2 is not typical because potassium can only form one bond, making this configuration unstable.
-
PH4 - Phosphorus can form more than 4 bonds, but in this case, P bonded to 4 hydrogens does not achieve a stable octet configuration (only 8 electrons).
Based on the analysis, the most stable configuration in chemical terms is represented by MgBr2.
So, the correct answer is: MgBr2