There are two different isotopes of bromine atoms. Under normal conditions, elemental bromine consists of Br₂ molecules, and the mass of a Br2 molecule is the sum of the masses of the two atoms in the molecule. The mass spectrum of Br₂ consists of three peaks: Mass (u) Relative Size 157.836 0.2569 159.834 0.4999 161.832 0.2431 (c) Determine the average molecular mass of a Br₂ molecule.

Video transcript

Hi everyone here we have a question telling us that sulfur has four naturally occurring stable isotopes, three of which 32 sulfur 33 sulfur, 34 sulfur are more abundant than the 4 36 sulfur. The mass spectrum of hydrogen sulfide H two s consists of three molecular ion peaks in our mass and atomic mass units. 33.987172 relative intensity of 94.99% 34.986560 atomic mass units, 0.7500%. And lastly 35. atomic mass units and 4.250% relative intensity. And our goal here is to calculate the average molecular weight for the hydrogen sulfide molecule. So we're going to do this by multiplying our atomic mass units times the relative intensity. And because the relativity relative intensity is in percentage, we're going to divide it by and we're going to add each peak, We're going to do this for each peak. So what that's going to look like is .98717, Times 94. Divided by 100 plus 34. times zero .7500, divided by 100 plus 35. Times 4. Divided by 100. And that is going to equal 34.08 atomic mass units. And that is our final answer, Thank you for watching Bye!