Answer:
1.65x10⁷ atoms of Al have to be laid side by side to span a distance of 2.36mm
Explanation:
We can assume Aluminium atoms as balls ordered side by side. As the radius of 1 atom is 143pm = 143x10⁻¹²m, the space that 1 atom occupies is 2 radius = 286x10⁻¹²m. That means to occupy 2.36mm = 2.36x10⁻³ you require:
2.36x10⁻³m ₓ ( 1 atom Al / 143x10⁻¹²m) =
1.65x10⁷ atoms of Al have to be laid side by side to span a distance of 2.36mm
