Ion that has both a positive and a negative charge, such as an amino acid in neutral solution. For example, glycine contains both a basic amino group (NH2) and an acidic carboxyl group (COOH); when these are both ionized in aqueous solution, the acid group loses a proton while the amino group gains one, and the molecule is positively charged at one end and negatively charged at the other.
Known as ‘white sun in blue sky’, the flag of Chinese revolutionary leader Sun Zhong Shan appears in the canton. The rays of the sun represent 12 traditional Chinese hours (each equalling two hours) symbolizing progress. Red is a traditional Chinese colour. Effective date: 8 October 1928.