(a) No. of moles of sodium = 46/23

= 2 moles

We know that one mole of sodium contains 6.022 x 10^{23} atoms. **∴** 2 moles of sodium contain = 2 x 6.022 x 10^{23} atoms

** = 1.204 x 10**^{24 }**atoms **

(b) 1 mole of oxygen = 32 g

32 g of O_{2} contains 6.022 x 10^{23} molecules

** ∴** 8 g of O_{2} contains = (6.022 × 10^{23} / 32) x 8 molecules

** = 1.51 x 10**^{23 }**molecules **

(c) 1 mole of carbon atoms contains 6.022 × 10^{23} atoms

** ∴** 0.1 mole of carbon atoms contains = 6.022 x 10^{23} x 0.1 atoms

** = 6.022 x 10**^{22 }**atoms**