Hi,
You didn't mention what "the following" were - please add additional information so the problem can be solved.
I think it is to help with plant growth, and converting nitrogen to ammonia.
Answer:
79.9 amu
Explanation:
Given data:
Atomic mass of bromine = ?
Percent abundance of 1st isotope = 50.7%
Atomic mass of 1st isotope = 78.92 amu
Percent abundance of 2nd isotope = 49.3%
Atomic mass of 2nd isotope =80.92 amu
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (50.7×78.92)+(49.3×80.92) /100
Average atomic mass = 4001.24 + 3989.36 / 100
Average atomic mass = 7990.6 / 100
Average atomic mass = 79.9 amu.
You need a control so you have something to compare the experimental group on-- If you don't have a control group, how will you know what's changed?
Answer:
there are 6 significant figures in 107.051