How many molecular orbitals are present in the conduction band of a lithium crystal with a mass of 11.2 g?

Video transcript

Everyone in this example, we have sodium crystal with a mass of 21.5 g. We need to calculate the number of molecular orbital is present in the conduction band of sodium crystal. So mapping out our solution, we're going to take our mass of sodium from the prompt. We're going to convert this into a value of moles. Then we want to find our number of atoms of sodium. Then we will move into finding our number of valence electrons and then from there we can find our number of molecular orbital's. So first looking for sodium on the periodic table, we would see that it's in group one a across period three. And so this means for the configuration of sodium, we have just one molecular orbital which would be our third energy level of the S. S sub level. And to get to our configuration of sodium, we would just have one electron in this three S sublevel filled in our single S orbital. We also want to recall from our periodic table our molar mass for sodium And we would see that that equals a value of 22.99 g per mole. So from the prompt, they gave us a value of 21.5 g of sodium and we want to go ahead and convert this to molds using our molar mass which we just stated is 22.99 g of sodium for one mole of sodium. So now we're able to cancel our units of grams. We're left with moles and as we stated, we want to get two atoms of sodium. So we're going to utilize avocados number as a conversion factor. Where we recall that for one mole of sodium Avocados number gives us 6.022 times 10 to the 23rd power sodium atoms. So now we're able to cancel out moles were left with atoms of sodium and from atoms of sodium. We want to go ahead and convert From our one sodium atom. Two the and sorry, that should say adam. We're converting from one sodium atom to the single three s electron in our sodium atom and moving everything over for more room so we can cancel out adam's now we're left with electrons and we want to recall that for this 13 s electron. We have just one molecular orbital for sodium and so we can go ahead and cancel out electrons leaving us with molecular orbital's as our final unit. And so what we should get here is a value equal to 5.63 times 10 to the 23rd Power Molecular Orbital's that will be present in the conduction band of our sodium crystal. So, this value here would be our final answer to complete this example. So, if you have any questions, please leave them down below. Otherwise, I will see everyone in the next practice video