Portland cement contains :-
$(I)$ $Ca_2SiO_4$ $(II)$ $Ca_3SiO_5$ $(III)$ $Ca_3Al_2O_6$

Which of the following is an amphoteric hydroxide?

Identify the incorrect reaction.

$A$ chemistry student wants to identify the metal ion in a salt. They make a paste of the salt with concentrated $HCl$ on a clean platinum wire loop. If they take a small amount of this paste and place it in a non-luminous flame,it produces a green flame. Which metal is present?

$(a)$ Give reactivity of alkaline earth metals towards air,water,dihydrogen and acids.
$(b)$ Explain reducing nature of alkaline earth metals.
$(c)$ Give chemical reaction of alkaline earth metals with liquid ammonia.

In India,during wedding ceremonies,a green flame is observed in fireworks. Which of the following elements is responsible for this?