Questions

A single spring season.

Potassium reacts violently with water liberating hydrogen. The reaction is so violent that the liberated hydrogen catches fire.

Helium has the highest First Ionization Energy in the Noble Gases group.

Ionization Energy ::

Ionisation energy is the energy required to remove one mole of electrons from one mole of gaseous atoms. Atoms are more stable when they have full valence shells.

Noble Gases have a very stable electron configuration, therefore, they have the highest amount of ionization energy within their periods. It decreases down a family because electrons farther from the nucleus are easier to remove.

Ionization Energy levels of Noble Gases group in Descending Order :: He, Ne, Ar, Kr, Xe, Rn

It is Blackboard or Chalkboard which is Black when clean, and as you write on it with white chalk it becomes dirty in White color.

Strait is nothing but a narrow passage of water which connects two seas or other large areas of water. Here Palk strait is the strait that separates India from Sri Lanka.