What is the use of amalgam alloys?

Which metals upon heating in the presence of air followed by hydrolysis give ammonia?

As compared to lithium,sodium reacts quickly with water because

Two elements $A$ and $B$ have similar chemical properties. They do not form solid hydrogencarbonates,but react with nitrogen to form nitrides. $A$ and $B,$ respectively,are :

Which of the following alkali metals has the least melting point?

The correct statement$(s)$ among $I$ to $III$ with respect to potassium ions that are abundant within the cell fluids is/are :
$I.$ They activate many enzymes
$II.$ They participate in the oxidation of glucose to produce $ATP$
$III.$ Along with sodium ions,they are responsible for the transmission of nerve signals