2.Identify the reactant compound in each of the following cases: • CO2 gas is evolved.
• Water vapour is the only gas evolved.
• Two different gases are evolved and the oxide residue remains.​

The ground state electron configuration of a phosphorous atom has  three unpaired electrons. they're in the 3p sublevel. the electron configuration is: , for a total of  15 electrons.

Silicon  6.0x10^23 is avogadro's number so the answer has to be 1 mole of whatever it is. since the molarity of silicon is equal to 28g/mol, this has to be the answer because 28g of si is 1 mole of si. 

Sink to the bottom. addition of potassium nitrate past it’s dissolution capacity at a particular temperature will cause the extra to just sink to the bottom of the glass.however, if you were to raise the temperature of the solution prior to dissolving it, and then slowly decrease the temperature after the dissolution, you would create a “supersaturated” solution - a solution that has more solute dissolved into it than should be allowed. if you add any extra solute past this, the entire solution would “crystallize,” and this is how you get those cool videos on youtube.