You have to note that pure substances can be elements or compounds. There is only one component all throughout. On the other hand, a mixture is a combination of different elements and compounds. They can appear in different phases. For example, air is a mixture. It is composed of pure substances of oxygen, carbon dioxide, and nitrogen.
All you have to do is a simple division "parts over the whole"
12.3 grams H/ 110 grams compound x 100= 11.2%
Answer:
<h3>Ocean crust is the relatively thin part of the earth's crust which underlies the ocean basins. It is geologically young compared with the continental crust and consists of basaltic rock overlain by sediments.</h3>
Boric acid, H3BO3, in aqueous solution would only give out one H+ ion. As it is also produce OH ion and by hydrolysis it produces one proton. <span>All the boron compounds (BX3) are having only 6 valence electrons in it and should follow the octet rule by taking another electron.</span>
B(OH)3 + 2 H2O → B(OH)4− + H3O