The answer is true. i’m sorry if i get this wrong.
A because if you multiple it, you will be moving the decimal one time
nitrogen-14, which makes up the vast majority of naturally occurring nitrogen, and nitrogen-15, which is less common.
These 2 isotopes are all of bromine that is naturally found (their percentages add up to 100%). In order to calculate the mean atomic mass, we can use the following calculation:

. This yields an average atomic mass of 79.903 amu. This procedure is general; whenever we have many types F of a specific genre G, the mean of the genre G can be calculated by:

where

is the proportion of type i in the genre G. In this example, Br79 and Br81 are the 2 types and the genre is Bromine.
··hydrogen peroxide if its wrong sorry i didnt pay atention much but i do remember the elemants being hydrogen peroxide and oxygen and copper so ya ω