1.
a student looked up the naturally occurring isotopes of bromine and found the following information:
50.54% of the naturally occurring isotopes of bromine have an atomic mass of 78.92 amu while 49.46% of the
naturally occurring isotopes of bromine have an atomic mass of 80.92 amu. calculate the average atomic mass of
bromine. show all work

The average atomic mass of bromine is 79.91 amu.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

  .....(1)

For isotope 1:

Mass of isotope 1 = 78.92 amu

Percentage abundance of isotope 1 = 50.54 %

Fractional abundance of isotope 1 = 0.5054

For isotope 2:

Mass of isotope 2 = 80.92 amu

Percentage abundance of isotope 2 = 49.46 %

Fractional abundance of isotope 2 = 0.4946

Putting values in equation 1, we get:

Hence, the average atomic mass of element bromine is 79.91 amu.

8 m/s because for him to get the same amount of energy as ray is putting out, bobby, who weighs half as much as ray, needs to run twice as fast.

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.