Make sure have same amounts of species on both sides
Cu (s) + 2 AgNO3 (aq) -> Cu(NO3)2 (aq) + 2 Ag (s)
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
Answer:
I think its 1.2 cause I divided 15.5 with 12 and got 1.2 as an answer
Answer:<span> a) the process for the first ionization energy
</span>
<span>Every time you take a electron you're requiring more and more energy. Expelling the first one
will require less energy than expelling the second and the second will
require less than the third, and so on.
When you take the first one, the atom becomes positive and with that the negative forces of the electron will be more attracted to the positive
charge. The more electrons that are lost, the
more positive this ion will become, causing it to be more difficult to separate the
electrons from the atom.
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