Question

Which of the following is not a Dobereiner's Triad?
a)Li,Na,K
b)He,Ne,Ar
c)Ca,Sr,Ba
d)Cl,Br,I​

Answer 1

Answer:

a)

Explanation:

lithium,sodium and potassium are traids bcz

li= atomic mass =6.9

Potassium=atomic mass= 39.1

so according to doberneir atomic mass of first element sums up with third element's atomic mass ÷2 is equal to atomic mass of second element ------simple formula to remember is A+B÷2

$0 6.9+39.1÷2

46÷2

23.0

$o the atomic mass of Sodium(Na) is 23.0

u can check it

HOPE IT HELPS