The atomic masses of $Cl$ and $I$ are $35.5$ and $127$ respectively. According to Dobereiner's law of triads,the atomic mass of $Br$ will be ............ .

Given below are the atomic masses of the elements:

Element	$Li$	$Na$	$Cl$	$K$	$Ca$	$Br$	$Sr$	$I$	$Ba$
Atomic Mass $(g \cdot mol^{-1})$	$7$	$23$	$35.5$	$39$	$40$	$80$	$88$	$127$	$137$

Which of the following does not form a $Dobereiner's$ triad?

Which scientist used atomic volume as the basis for the periodic classification of elements?

The law of triads is applicable to a group of

What is the periodic table according to Glenn $T$. Seaborg?

State whether the following statements are true or false:
$(i)$ The first periodic table was proposed by Dobereiner.
$(ii)$ The law of octaves was proposed by Newlands in $1865$.
$(iii)$ Mendeleev was the first to propose the periodic law.
$(iv)$ Mendeleev named Eka-aluminium as Germanium and Eka-silicon as Gallium.