Bromine has 2 isotopes Br-79 and Br-81. The smaller isotope is 51% of the atoms on earth. Br-81 accounts for 49%. Set up the problem exactly as instructed and calculate the AVERAGE ATOMIC MASS. In the text box write Br-81 in NUCLEAR NOTATION.

@gelphielvr

Question

Bromine has 2 isotopes Br-79 and Br-81. The smaller isotope is 51% of the atoms on earth. Br-81 accounts for 49%. Set up the problem exactly as instructed and calculate the AVERAGE ATOMIC MASS. In the text box write Br-81 in NUCLEAR NOTATION.

@gelphielvr

Luigi0210 · Answer

So to break it down, we are given Br-79 and Br-81.

Br-79 makes up 51% and Br-81 makes up 49%.

What you need to do is find the AMU (atomic mass unit) given Br-79 and Br-81.

Luigi0210 · Answer

So something like this:

$\Large (79 amu * 0.51) + (81 amu * 0.49)   $

$\Large 40.29 + 39.69 $

Adding them should give you average AMU of 79.98

Luigi0210 · Answer

And notation wise it would look something like $\Large ^{81}_{35}B $

Luigi0210 · Answer

*Br not B

Luigi0210 · Answer

And I found the AMU from their isotope number, i.e. Br-79 is 79 amu

gelphielvr · Answer

idk if I can comment here but thank you this actually helped :]