Compounds with quadrivalent chiral atoms other than carbon.

•	Any molecule containing an atom that has four bonds orientated towards the corners of a tetrahedron will be optically active if the four groups are different. For an example of a compound with a quadrivalent chiral Si atom see refcodes: YONMET and YONMIX.

•	Examine each of these two stereoisomers in turn. Assign R or S configuration to the Si atom in each structure.