The alkali metal halides are soluble in water but $LiF$ is insoluble because

How many of the following metals give oxides and nitrides when burnt in air?
$Be, Na, Mg, Ba, Sr, Li, K$

Fill in the blanks:
$(1)$ Lithium on reaction with nitrogen present in air is denoted by .....
$(2)$ Potassium gives ...... colour in oxidizing flame.
$(3)$ ....... and ........ metals are used in photoelectric cells.
$(4)$ When alkali metal dissolves in ammonia,it produces a blue-coloured solution. This colour is due to .......

Choose the false statement regarding the properties of sodium hydroxide $(NaOH)$.

Which of the nitrates on strong heating leaves the metal as the residue?

Sodium metal on dissolution in liquid ammonia gives a deep blue solution due to the formation of: