HELP PLEASE THIS IS CONFUSING

Number of moles = 8.3 x 10⁻¹³

The mole is the number of particles(molecules, atoms, ions) contained in a substance

1 mol = 6.02.10²³  particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's =  6.02.10²³

5 x 10¹¹ atoms of Silver :

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer