Respuesta :

Density gives mass of object per volume......   Here, density is given 8.90 g/cm3   therefore, per cubic centimeter contains 8.90 g Ni.   mole of Ni = mass / atomic mass   = 8.90 / 58.6934   = 0.1516 mole     number of atoms: mole * 6.022 * 10^23   = 0.1516 * 6.022 * 10^23   = 0.9129 * 10^23   = 0.9 * 10^23 (approx.)