Answer:
[tex]{5.11 * 10^{23} atoms Na}[/tex]
Explanation:
[tex]{26.3 g} {Na_{2}O}[/tex] * [tex]\frac{1 mol Na_{2}O}{61.979 g Na_{2}O}[/tex] * [tex]\frac{2 mol Na}{1 mol Na_{2}O}[/tex] * [tex]\frac{6.022*10^{23} atoms Na}{1 mol Na}[/tex]
= [tex]{5.11 * 10^{23} atoms Na}[/tex]