Answer: Charles's law, Avogadro's law andd Boyle's law.
Charles law states the constant ratio of volume to temperature, at constant pressure. Boyle's law states the constat product of pressure and volumen at constant temperature. Avogadro's law states that equal volumes of gases at the same temperature and pressure have equal number of particles.
So, all those three laws combined state the relation of pressure, volume, temperature and number of particles of a gas, which is what the ideal gas law does: PV = n RT.
Method:
1) Find the atomic number in a periodic table: the number of electrons equal the atomic number
2) Use Aufbau rule
Element atomic number electron configuration
<span>
P 15 1s2 2s2 2p6 3s2 3p3
Ca 20 </span><span><span>1s2 2s2 2p6 3s2 3p6 4s2
</span>Si 14</span><span> 1s2 2s2 2p6 3s2 3p2
S 16</span><span><span> 1s2 2s2 2p6 3s2 3p4
</span>Ga 31. </span><span><span> 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p</span> </span>