How can I understand which valence is applicable in a bond of molecule containing changeable valence?

Which orbitals form a pi bond? a.the s orbital and three p orbitals b.the s orbital and two p orbitals c.overlapping p orbitals d.overlapping hybrid orbitals

Which of the following describes a situation where competition between producers exists

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.