This Celtic symbol of everlasting love is formed from two triskeles. The triskeles, three cornered knots, denote the three aspects of two people, body, mind and spirit. The two triskeles, joined together, show a circle, the everlasting circle of eternity.
All the others are weak acids. A strong acid is one that dissociates completely when it dissolves in water. Dissociate means that the substance splits apart into ions. There are only a few strong acids in water, they are: HBr, HCl, HI, HNO3, HClO4 and H2SO4 (for the first H only) All other acids are weak acids. Chemists use the term strong or weak with regard to acids and bases to tell how much the substance dissociates in water.
As opposed to this, hydrogen bonds are intermolecular, that is, occur between molecules or between different parts of one molecule. The hydrogen bonds are pretty strong; stronger than van der Waals forces but are weaker than covalent and ionic bonds.