Answer:
7
Explanation:
Atomic number of X = 3
Atomic mass of X = 6.94 amu
1st isotope atomic mass = 6 amu
2nd isotope atomic mass = 7 amu
Which is more abundant isotope = ?
Explanation:
we know there are two naturally occurring isotopes of given element X, X-6 and X-7.
First of all we will set the fraction for both isotopes
x for the isotopes having mass 6
1-x for isotopes having mass 7
The average atomic mass of X = 6.94 amu
we will use the following equation,
6x + 7 (1-x) = 6.94
6x + 7 - 7x = 6.94
6x- 7x = 6.94 - 7
-1x = -0.06
x= -0.06/-1
x= 0.06
0.06 × 100 = 6%
6% is abundance of X-6 because we solve the fraction x.
now we will calculate the abundance of X-7.
(1-x)
1-0.06 =0.94
0.94 × 100= 94%
94% for X-7.
