The hydration energy of $Mg^{2+}$ is

The electronic configuration of a metal is $1s^2 2s^2 2p^6 3s^1$. The formula of its oxide is:

In some respects,lithium differs from other alkali metals. Which of the following is the main reason for this?

Alkali metals are powerful reducing agents because

$NaOH$ can be transported in the container made up of ?

Fill in the blanks:
$(1)$ ......... method is used to prepare sodium carbonate.
$(2)$ Sodium carbonate exists as .........
$(3)$ Sodium chloride is commonly known as .........
$(4)$ Sodium chloride melts at ......... temperature.