Answer:
a) Platinum > Beryllium > Aluminum > Magnesium > Potassium > Cesium
b) Cesium > Potassium > Magnesium > Aluminum > Beryllium > Platinum
c) Cesium > Potassium
Explanation:
We must recall that the frequency of an electromagnetic wave is directly proportional to its energy. Hence as the work function of the metal increases, the minimum frequency required for emission of electrons occur increases accordingly.
Similarly, the maximum wavelength required for electron emission to occur varies inversely as the work function of the metal hence the answer provided.
Lastly, only caesium and potassium has work function less than the energy of the incident photon hence only these two metals experience electron emission with the kinetic energy of electrons emitted from caesium greater than that emitted from potassium.
Explanation:
I know only P2O5 = Phosphorus pentoxide
The balanced equation is
4Fe+3O₂⇒2Fe₂O₃
We know that the mole of Fe₂O₃ is 6, and since the ratio between oxygen and <span>Fe₂O₃ is 3:2, we can see that
3:2 = x:6 (3 oxygen moles can make 2 </span>Fe₂O₃ moles = x oxygen moles can make 6 <span>Fe₂O₃ moles)
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Multiply outside and inside (3*6 , 2*x) and put them on opposing sides of the equation
2*x = 3*6
2x=18
x=9
Therefore 9 moles of oxygen is needed.
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The air particles in the bubble are forced to expand when we pull up on the plunger.
<h3><u>Explanation:</u></h3>
Pulling creates a large amount of volume , when the volume of the air bubble is increased, air particles inside the bubble tries to accumulate all of the volume by expanding the size of the bubble. Since according to Ideal gas law,
P V = n R T
where P = Pressure of the gas
V = Volume of the gas
n = No. of moles
R = Boltzmann's constant
T = Temperature
We can observe that pressure is inversely proportional to the volume of the gas. Therefore, when we pull up the plunger, the volume of the air bubble is increased and the pressure inside it is decreased.