The atomic masses of Li and K are 7 and 39, respectively . According to law of triads the atomic mass of Na will be

Lithium, sodium and potassium form a Dobereiner's triad. The atomic masses of lithium and potassium are 7 and 39 respectively. Predict the atomic mass of sodium.

Three elements X, Y and Z follow Doberiner's law of traids. If atomic masses of X and Z are 7 and 39 respectively, then determine the atomic mass of Y.

In a triad of three elements A, B, and C, the atomic mass of A and B are 80 and 120 respectively. Find the atomic mass of element C.

According to law of conservation of mass:

Cl, Br, I follows Dobereiner's triads, the atomic masses of Cl and I are 35.5 and 127 respectively. The atomic mass of Br is :

Chlorine, Bromine and Iodine form a Dobereiner’s triad. The atomic masses of Chlorine and iodine are 35.5 and 126.9 respectively. Predict the atomic mass of Bromine.

In Dobereiner's triads Li, Na, K the atomic masses of lithium and potassium are 6.9 and 39.1 respectively, then what will be the atomic mass of sodium?