00:01
Here given mass of silicon msi is equal to 100 kilogram is equal to 100 multiplied by 10 to the power 3 gram and the density of silicon rho is equal to 2 .33 gram per centimeter cube.
00:34
Therefore, volume of silicon vsi in 100 kilogram is equal to msi divided by rho is equal to 100 multiplied by 10 to the power 3 divided by 2 .33 is equal to 42918 .45 centimeter cube.
01:10
In 1 centimeter cube of silicon 10 to the power 18 boron atoms are needed.
01:30
Therefore, 42918 .45 centimeter cube silicon 10 to the power 18 multiplied by 42918 .45 boron atoms needed that is equal to 4 .292 multiplied by 10 to the power 22 boron atoms.
02:22
Number of moles of boron needed is equal to 4 .292 multiplied by 10 to the power 22 divided by n a.
02:47
N a is the avogadro number which is equal to 6 .022 multiplied by 10 to the power 23.
03:01
Therefore, is equal to 4 .292 multiplied by 10 to the power 22 divided by 6 .022 multiplied by 10 to the power 23 is equal to 0 .0712 mole.
03:31
Therefore, mass of boron needed is equal to number of moles multiplied by molar mass which is equal to 0 .0712 multiplied by 10 .811.
04:15
Molar mass of boron is 10 .811.
04:18
Therefore, by calculating we will get 0 .7689 gram...