Answer:
30 atoms
Step-by-step explanation:
2Ni(H₃O₄)₂
There are two nickel, twelve hydrogen and sixteen oxygen atoms are present in given formula.
The given formula is actually having two moles of Ni(H₃O₄)₂.
Thus in two mole total number of atoms are = 2+12+16 =30 atoms
In one mole there are one nickel atom, six hydrogen atom and eight oxygen atoms are present.
Thus in one one mole total number of atoms are = 1+6+8 =15 atoms
However this compound does not exist.