This problem is asking for the percent by mass of hydrogen in hydrofluoric acid. At the end, the answer turns out to be D. 5% as shown below:
<h3>Percent compositions:</h3>
In chemistry, percent compositions are used for us to know the relative amount of a specific element in a compound. In order to do so for hydrogen, we use the following formula, which can also be applied to any other element in a given compound:

Where
stands for the atomic mass of hydrogen and
for the molar mass of hydrofluoric acid. In such a way, we plug in the atomic masses of hydrogen (1.01 g/mol) and fluorine (19.0 g/mol) to obtain:

Learn more about percent compositions: brainly.com/question/12247957
The region is located on an active oceanic plate
Answer:
it is Glucose hope it helps
It is an open series circuit and this is why:
its obvious its a series circuit because all the symbols are in a straight rectangle.
its an open circuit because an open circuit has something that doesn't allow the electrons to flow all the way. and the thing blocking the electrons it the switch which is open, (off).
Hope this helped!! sorry its late!!
Answer:
I think the answer is B)the processes in which molecules interact to form new subtances.