3) Most of the rocks in Earth's crust are silicates. Silicates contain combinations of silicon dioxide (SiO2) and various other
minerals. Why does that make sense given the percentages of elements
available within the Earth system?

What overall charge must all compounds have

In a reaction (at equilibrium) that makes more moles of gas than it consumes, what is the effect of increasing the pressure?

If a molecule with a molecular formula of c13h18 is treated with an excess of h2 in the presence of finally divided pt metal under conditions required for maximum hydrogenation of the molecule to give a molecule with a formula c13h24, how many rings are in the molecule?