If you really want to find out the answer just pray about it and it will come to you..
Answer:
If I remembered correctly the answer would be Ne and Ar(Neon and Argon
The percent difference between two numbers
and
is given by

The absolute value is there because we only care about the absolute percent difference, and not taking into account whether we go from
to
or vice versa. If we remove them, we have two possible interpretations of percent difference.
For example, the (absolute) percent difference between 3 and 6 is

In other words, we add 100% of 3 to 3 to end up with 6. This is the same as the percent difference going from 3 to 6. On the other hand, the percent difference going from 6 to 3 is

which is to say, we take away 50% of 6 away from 6 to end up with 3.
"Make comparisons to object measurements" tells us that the differences should be computed relative to "measurements for object". In other words, take
from the left column and
from the right column.


