1.

Li, Na, K are Dobereiner triads. If the atomic weight are 7 and 39 respectively then what would be the atomic weight of Na ?

Answer»

Solution :Li (Lithium) = 7 atomic number
K (Potassium) = 39 atomic number
MIDDLE element of triads is NA
` :. ` Atomic weight of sodium = `((Li +K))/2= (7 + 39)/2 = 46/2 = 23`


Discussion

No Comment Found