The mass of a nickel coin is 5 g.
1 mol of Ni weighs 58 g. 1 mol contains 6.022 x 10²³ atoms of Ni.
therefore in 58 g there are 6.022 x 10²³ atoms of Ni
then in 5 g the number of Ni atoms are - 6.022 x 10²³ /58 x 5 = 5.2 x 10²² Ni atoms
Therefore number of Ni atoms are 5.2 x 10²² atoms in a nickel coin
What depends on the type of acid some acid you have to use plastic or aluminum to store
Zinc (Zn) has less than 34 protons, 30 to be exact, and is a transition metal in Group 12. Note: it is also called a "post-transition metal."