What tells the mole ratio of the reactants and products in the chemical equation?

According to the vsepr theory what is the shape of a molecule that has a central atom valence three other items with no lone pairs of electrons

The missing component to the table to the right or indicated with orange letters complete the table by filling in the corresponding numbers or symbols

Asample of hydrated tin (ii) chloride (sncl2) has a mass of 4.90 g. when it is dehydrated, it has a mass of 4.10 g. which is the correct chemical formula for the hydrate? sncl2•2h2o          sncl2•4h2o          sncl2•6h2o