In this case, we are going to assume that there are 100 atoms to make things easier.
Let R% be the abundance of n-15. With this in mind, we calculate the abundance of n-14 to be 100%-R%
14.0031*(100-R)% + 15.001 * R%= 14.00674
In this case, we can delete or ignore the % sign since we do not want to carry it around, however, we need to keep in mind that the final answer is in %
14.0031*(100-R) + 15.001 * R= 14.00674
1400.31-14.0031R+15.001R=1400.674
0.9979R=0.364
R=0.3648
Then, the abundance of n-15 is 0.3648%
I would love to help but it is 3 or is it 3 million?
<h2>Hello!</h2>
The answer is: False.
Why?
It's known that most common galaxies are spiral - shaped, but according to some studies, the irregular - shaped galaxies can not be even considered "spiral shaped".
Irregular - shaped are galaxies defined by their lack of structures, and they were formed by an external gravitonal force acting, in fact, it's believed that they were spiral or elliptical galaxies before.
An example of irregular - shaped galaxies is Small Magenallic Cloud.
Have a nice day!