Four reactions are given below:
$(i)$ $2Li + 2H_2O \to 2LiOH + H_2$
$(ii)$ $2Na + 2H_2O \to 2NaOH + H_2$
$(iii)$ $2LiNO_3 \xrightarrow{\text{Heat}} 2LiNO_2 + O_2$
$(iv)$ $2NaNO_3 \xrightarrow{\text{Heat}} 2NaNO_2 + O_2$
Which of the above,if any,is wrong?

$Cs^{+}$ ions impart violet colour to Bunsen flame. This is due to the fact that the emitted radiations are of

Potassium permanganate,on heating,gives:

State True or False:
$(1)$ Half-life of $^{223}Fr$ is $21 \ s$.
$(2)$ $Li^{+}$ has a high hydration enthalpy and therefore its salts are usually hydrated in nature.
$(3)$ Among all the alkali metals,only $Na$ can react with nitrogen of air and form a nitride.
$(4)$ Except $LiF$,other halides of $Li$ are soluble in water.

The disease known as fluorosis is caused by the reaction of excess fluorine in the body with which of the following?

How is magnesium obtained from the following?