Phosphonic acid $(H_3PO_3)$ is:

Write a note on $p$-block elements of the periodic table.

Illustrate how copper metal can give different products on reaction with $HNO_3$.

Consider the following Assertion $(A)$: Phosphorus can form both phosphorus$(III)$ and phosphorus$(V)$ chlorides, but nitrogen cannot form nitrogen$(V)$ chloride. Reason $(R)$: The electronegativity of nitrogen is more than that of phosphorus. The correct answer is

The metal which displaces hydrogen from a boiling caustic soda solution is

When $AgNO_3$ is heated strongly,the products formed are