Answer:
79.986
Step-by-step explanation:
Let A represent isotope ⁷⁹Br
Let B represent isotope ⁸¹Br
From the question given above, the following data were obtained:
For Isotope A (⁷⁹Br):
Mass of A = 79
Abundance of A (A%) = 50.69%
For isotope B (⁸¹Br):
Mass of B = 81
Abundance of B (B%) = 49.31%
Relative atomic mass of Br =?
The relative atomic mass (RAM) of Br can be obtained as follow:
RAM = [(Mass of A × A%) /100] + [(Mass of B × B%) /100]
= [(79 × 50.69) /100] + [(81 × 49.31) /100]
= 40.0451 + 39.9411
= 79.986 amu
Thus, the relative atomic mass of Br is 79.986
Answer: y=300⋅2.03x
Step-by-step explanation:
If the amount of money you invested in the first fund is x and the second fund y, then 9% (or 0.09 by moving the decimal 2 spots)*x+0.03*y=1047 since the first fund paid 9% and the second 3%. In addition, for this year, we get
0.1*x+0.01*y=811.
We also have 0.09*x+0.03*y=1047, so we can multiply the top equation by -3 and add it to the second to get -0.21x=-1386. Dividing both sides by -0.21, we get x=6600. In addition, since 0.1*x+0.01*y=811, we can plug 6600 in for x to get 660+0.01*y=811 and by subtracting 660 from both sides we get 0.01*y=151. Multiplying both sides by 100 (since 0.01*100=1), we get y=15100
