Which tricyclic antidepressant possesses the least antihistaminergic activity?

The correct answer is desipramine hydrochloride.  

Desipramine hydrochloride is the least potent tricyclic antidepressant at both the histamine H1 and the muscarinic acetylcholine receptors.  

The TCAs or tricyclic antidepressants refers to a category of medicines, which are used mainly as antidepressants. Desipramine is sold by the brand name Pertofrane and Norpramin among the others and is a TCA that is used in the treatment of depression.  

It functions as a comparatively selective norepinephrine reuptake inhibitor, however, it also does other activities, like an antihistamine and anticholinergic effects.  

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.