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

Among the following ions,the $p\pi - d\pi$ overlap could be present in:

Which of the following overlaps is incorrect (assuming $Z$-axis is the internuclear axis)?
$(A)$ $2p_y + 2p_y \to \pi$-bond formation
$(B)$ $2p_x + 2p_x \to \sigma$-bond formation
$(C)$ $3d_{xy} + 3d_{xy} \to \pi$-bond formation
$(D)$ $2s + 2p_y \to \pi$-bond formation
$(E)$ $3d_{xy} + 3d_{xy} \to \delta$-bond formation
$(F)$ $2p_z + 2p_z \to \sigma$-bond formation

What is the number of $\sigma$ and $\pi$ bonds in the resonance structure of benzene?

The nodal plane in the $\pi-$bond of ethene is located in

Which of the following represents the nodal plane in the $\pi$-bond of ethene $(C_2H_4)$?