The atoms form positive and negative ions which attract to each other. Ionic compounds are composed of large numbers of positive ions (cations) and negative ions (anions) so that the amount of positive charge equals the negative charge. In covalent bonds the electrons are shared between two bonded atoms.
4. Try doing a gradation of color by selecting a shirt and tie that are the same color, but in lighter or darker shades. For example, pair a light blue dress shirt with a medium blue tie. 5. For business interviews and important meetings, keep your tie color classic and conservative.
Traditionally worn only for events after 7 p.m., black tie is less formal than white tie but more formal than informal or business dress. In the United States, the gentlemen's form of black tie attire is often referred to as a tuxedo.