The quantum numbers +1/2 and -1/2 for the electron spin represent

The common features among the species CN^-, CO and NO⁺ are :

The set representing the correct order of first ionization potential is

The triangle formed by the tangent to the curve $$f\left( x \right) = {x^2} + bx - b$$ at the point $$(1, 1)$$ and the coordinate axex, lies in the first quadrant. If its area is $$2$$, then the value of $$b$$ is