Answer :
Option C) 2.5 units
Explanation : For calculating the strength of a unknown magnetic field in comparison with the given magnetic field we can use the magnetic formula as;

On substituting the values we get;

;
On solving we get the magnetic B field strength as
2.5 units
This material has a density of 1 g/cm3.
(since 12.48 g/ 12.48 cm3 = 1 g/cm3)
Therefore, this material is water.
There are:
3.41 moles of C
4.54 moles of H
3.40 moles of O.
Why?
To solve the problem, the first thing that we need to do is to write the chemical formula of the ascorbic acid.

Now, we know that there are 100 grams of the compound, so, the masses of each element will represent the percent in the compound.
We have that:

To know the percent of each element, we need to to the following:

So, we know that for the 100 grams of the compound, there are:
40.92 grams of C
4.58 grams of H
54.49 grams of O
We know the molecular masses of each element:

Now, to calculate the number of moles of each element, we need to divide the mass of each element by the molecular mass of each element:

Hence, we have that there are 3.41 moles of C, 4.54 moles of H, and 3.40 moles of O.
Have a nice day!