Polyhydroxyl alcohols are alcohols with more than one hydroxyl group attached to a carbon sequence. true or false?

Answer is: True.

Example for polyhydroxyl alcohol is glycerol.
Glycerol (1,2,3-Propanetriol, glycerine or glycerin) is a simple polyol (it has three hydroxyl group) compound with formula (OH-CH₂-CH(OH)-CH₂OH or C₃H₈O₃). 
The glycerine backbone is found in all lipids known as triglycerides. (ester derived from glycerol and three fatty acids).
Glycerol is soluble in water and it is hygroscopic.

☆ionisation energy increases across a period from na -> ar☆ionisation energy decreases down a group from li -> fr☆ionic radius decreases across a period from na -> cl☆ionic radius increases down a groupfrom f -> ii hope it clarifies your doubts