Answer is A. The reason to create such is to conduct electricity, and metal conducts electricity.
Hope this helps, Tiara
1) Carbon-13:
Proton-6 Neutron-7 Electron-6
2)Atomic mass of element X:
(55*10+56*20+57*70)/100=56.6
Given the concentration of aniline hydrochloride is 
Aniline hydrochloride is the conjugate acid of aniline a weak base.
pH can be calculated from 
anilinium ion the conjugate acid of aniline.
Answer:
In 1 mol of Pb₃(PO₄)₄ occupies 1001.48 grams
Explanation:
This compound is the lead (IV) phosphate.
Grams that occupy 1 mole, means the molar mass of the compound
Pb = 207.2 .3 = 621.6 g/m
P = 30.97 .4 = 123.88 g/m
O = (16 . 4) . 4 = 256 g/m
621.6 g/m + 123.88 g/m + 256 g/m = 1001.48 g/m
