compound
Silicon Oxide is not an element; it is a compound.
There is one silicon atom and one oxygen atom in the compound SiO.
There is no such compound, so it's kind of pointless attempting to name it. Well actually, the chemical name of SiO is Silicon Monoxide. You use the prefix mono- because there is only one oxygen.
This compound is silicon dioxide - SiO2.The oxide SiO is not yet accepted.
element. Sulfur dioxide (SO2) is a compound
KCl is a compound not an element.
Beryllium is an element. It is not a compound
cornstarch is a compound element.
it is a compound
I don't believe it to be, considering the fact that the silicon is combined with oxygen. Pure substances to my understanding is one single element alone, and SiO is not. But I can look at it from another definition of pure substance and say that it is due to the fact that it is SiO without anything else containing it, or anything its being stored in.
Mixture
If two elements (A and B) form more than one compound between them, then the ratios of the masses of the second element (B) which combine with a fixed mass of the first element (A) will be ratios of small whole numbers. Examples: CO, CO2 SO, SO2, SO3 SiO, SiO2 NO, NO2