Question

an element x is atomic number 3, relative atomic mass 6.94 and consist of two isotopes of mass number 6 and 7 respectively .calculate the relative abundance of each isotope

Answer 1

Answer:

It’s a simple 2 variable algebra problem. I will solve with the substitution method.

6x + 7y = 6.94

x + y = 1

Therefore

x + y = 1

x + y – x = 1 – x

y = 1 – x

Substitute y for (1 – x)

6x + 7(1 – x) = 6.94

6x +7 – 7x = 6.94

7 – x = 6.94

7 – x – 7 = 6.94 – 7

–x = –0.06

x = 0.06

So 6% mass 6. The remaining 94% would be mass 7.