Bond which is formed by sidewise overlapping of $2p$-orbitals of chalcogen atom is present in :

State the differences between sigma $(\sigma)$ and pi $(\pi)$ bonds.

Given below are two statements :
Statement $(I)$ : The oxidation state of an element in a particular compound is the charge acquired by its atom on the basis of electron gain enthalpy consideration from other atoms in the molecule.
Statement $(II)$ : $p\pi-p\pi$ bond formation is more prevalent in second period elements over other periods.
In the light of the above statements,choose the most appropriate answer from the options given below :

Which of the following molecules has two $\sigma$ and two $\pi$ bonds?

What is the total number of $\pi$ bonds in the compound $CH_2=CH-CH=CH-COOH$?

If the internuclear axis is the $z$-axis,then in which of the following cases are $\sigma$ and $\pi$ bonds not possible?