2Ca + O2 = 2CaO
First, determine which is the excess reactant
72.5 g Ca (1 mol) =1.8089725036
(40.078 g)
65 g O2 (1 mol) =2.0313769611
(15.999g × 2)
Since the ratio of to O2 is 2:1 in the balanced reaction, divide Ca's molar mass by 2 to get 0.9044862518. this isn't necessary because Ca is already obviously the limiting reactant. therefore, O2 is the excess reactant.
Now do the stoichiometry
72.5 g Ca (1 mol Ca) (1 mol O2)
(40.078 g Ca)(2 mol Ca)(31.998g O2)
=0.0282669621 g of O2 left over
Henlo!
Bohr's model was unable to calculate or it required precise information about position of an electron and its velocity. It is very difficult to calculate velocity and position of an electron at the same time because electron i too small to see and may only be observed if peturbed, for example we could hit the electron with another particle such as photon or an electron, or we could apply electric or magnetic field to the electron. This will inevitably change the position of the elctron or its velocity and direction. Heisenberg aid that more precisely we can define the position of an electron, the less certainity we are able to define its velocity and vice versa.
In short, first option is correct one
Answer is:
The sun's energy is transferred through the vacuum of space to Earth
According to Raoult's law, Vapor pressure is directly proportional to the mole fraction of the solution. As 1.0 M CaF2 has least moles here, it has lowest vapor pressure.
In short, Your Answer would be Option D
Hope this helps!
