Assuming that Hund’s rule is violated, the bond order and magnetic nature of the diatomic molecule B₂ is

The species having pyramidal shape is

The total number of diprotic acids among the following is:

H₃PO₄, H₂SO₄, H₃PO₃, H₂CO₃, H₂S₂O₇, H₃BO₃, H₃PO₂, H₂CrO₄ and H₂SO₃

Two parallel chords of a circle of radius 2 are at a distance $$\sqrt 3 + 1$$ apart. If the chords subtend at the center , angles of $${\pi \over k}$$ and $${{2\pi } \over k},$$ where$$k > 0,$$ then the value of $$\left[ k \right]$$ is

[Note :[k] denotes the largest integer less than or equal to k ]