Question

please say 6th question who will say with explanation I will give brain list and I will follow them ​

Answer 1

Answer:

a) Li , Na , K

Step-by-step explanation:

Mass No. of Li = 7

Mass no. of Na = 23

Mass no. of K = 39

So , in a Dobereiners Triad , the mass of the middle element is equal to the average of the other two.

So ,

$\frac{7 + 39}{2} = 23$

[ Proved ]