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
Titanium has an atomic number of 22, which means it has 22 protons and 22 electrons. About 73.8 percent of natural titanium exists as the isotope Ti-48, which contains 26 neutrons.
Bromine has 35 protons, and in this case 46 neutrons, so 35 + 46 = 81
Therefore, the symbol is (subscript 35)(superscript 81) Br.
it does not freeze in the fridge, merely turns to a solid state. how long would depend on how warm it was before you put it in the fridge.
Vinegar is a mixture cause its composed of water and acetic acid.
