Mass of Lithium = 1443.73 g ≈ 1.4 kg
Further explanation
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
The number of atoms of Li = N=1.25 x 10²⁶
mol Li(n) :
[tex]\tt n=\dfrac{N}{No}\\\\n=\dfrac{1.25\times 10^{26}}{6.02\times 10^{23}}\\\\n=2.08\times 10^2[/tex]
mass Li (Ar=6.941 g/mol)
[tex]\tt mass=mol\times Ar\\\\mass=208\times 6,941\\\\mass=1443.73~g[/tex]
