Which type of bond is found between na+ and cl- ions in nacl?

Ionic bond. Remember that Na really wants to get rid of its one valence electron, while Cl wants to get one electron to complete its valence shell. There's an electrostatic bond between these two ions, so hence it's ionic. 

If the water vapor content stays the same and the temperature drops, then the relative humidity increases. its vise versa.if the water vapor content stats the same and the temperature rises, the relative humidity decreases. so, yes, i'd say that temperature and humidity have a strong relationship.

The reaction will shift to the right