The most appropriate answer is Second one !! as there are acids , bases in the water thus they make the pH variable !!
Atomic mass platinum = <span>195.084 a.m.u
195.084 g -------------- 6.02x10</span>²³ atoms
?? g -------------------- 5.22x10²¹ atoms
( 5.22x10²¹) x 195.084 / 6.02x10²³ => 1.691 g
hope this helps!
When two atoms combine by transferring electrons, it is an ionic bond. For example, <span>LiF - Lithium Fluoride is an example of an ionic bond.</span>