Each element absorbs light at specific wavelengths unique to that atom. When astronomers look at an object's spectrum, they can determine its composition based on these wavelengths.
Not sure if this is 100% but I hope it helps.
I hope this helps you alot and to my understanding:)
Iron (III) chloride catalyzes the decomposition of hydrogen peroxide because the decomposition of hydrogen peroxide is usually inhibited by the presence of ions such as phosphate ions in solution. The iron ions that would result from the dissolution of iron (III) chloride have a charge of 3+ and would bond with the -3 charged phosphate ions, creating a non-charged FePO4 molecule and removing the decomposition inhibitor from the solution. Potassium iodide and potassium chloride both are more strongly bonded than a transition metal compound and would lack the necessary charged iron ion when added to hydrogen peroxide.
C) the number of the pricipal energy level containing the outer electrons increases
Given the temperature 746 K and activity of Pb equal to 0.055. The mole fraction of Pb is 0.1. So, the mole fraction of Sn = 0.9.Activity coefficient, γ = 0.055 / 0.1 = 0.55.The expression for w=ln〖γ_Pb x RT〗/(X_Sn^2 )=(-0.5978 x 8.314 J/(mol K ) x 746 K)/(0.9 x 0.9)= -4577.7 J= -4578 J
Now we use the computed value above and new temperature 773 K. The mole fraction of Sn and Pb are 0.5 and 0.5 respectively. Calculate the activity coefficient in the following manner.lnγ_Sn=w/RT X_Pb^2=(-4578 J)/(8.314 J/mol x 773 K) x 0.5 x 0.5= -0.718lnγ_Sn=exp(-0.178)=0.386The activity of Sn= γ_Sn x X_Sn=0.386 x 0.5=0.418
w of the system is -4578 J and the activity of Sn in the liquid solution of xsn at 500 degree Celsius is 0.418