Which of the following elements exhibits the usual tendency to undergo reduction?

Which of the following processes occurs during the reaction of $Cu$ with $AgNO_3$ solution?

When ammonia is heated with cupric oxide,the ammonia molecule $.......$

Observe the following reactions:
$I$. $2H_2O_{(l)} + 2Na_{(s)} \rightarrow 2NaOH_{(aq)} + H_{2(g)}$
$II$. $2H_2O_{(l)} + 2F_{2(g)} \rightarrow 4H^{+}_{(aq)} + 4F^{-}_{(aq)} + O_{2(g)}$
Identify the correct statement from the following:

Which of the following represents the most oxidized form of hydrocarbon?

In an acidic medium,when $KMnO_4$ is reduced by oxalic acid,what is the change in the oxidation state of $Mn$?