Nonmetals are further to the right on the periodic table, and have high ionization energies and high electron affinities , so they gain electrons relatively easily, and lose them with difficulty.
They also have a larger number of valence electrons, and are already close to having a complete octet of eight electrons. The nonmetals gain electrons until they have the same number of electrons as the nearest noble gas Group 8A , forming negatively charged anions which have charges that are the group number minus eight. That is, the Group 7A nonmetals form 1- charges, the Group 6A nonmetals form 2- charges, and the Group 5A metals form 3- charges. The Group 8A elements already have eight electrons in their valence shells, and have little tendency to either gain or lose electrons, and do not readily form ionic or molecular compounds.
Ionic compounds are held together in a regular array called a crystal lattice by the attractive forces between the oppositely charged cations and anions. These attractive forces are very strong, and most ionic compounds therefore have very high melting points. Ionic compounds are typically hard, rigid, and brittle. Ionic compounds do not conduct electricity, because the ions are not free to move in the solid phase, but ionic compounds can conduct electricity when they are dissolved in water.
When nonmetals combine with other nonmetals, they tend to share electrons in covalent bonds instead of forming ions, resulting in the formation of neutral molecules. Keep in mind that since hydrogen is also a nonmetal, the combination of hydrogen with another nonmetal will also produce a covalent bond. Molecular compounds can be gases, liquids, or low melting point solids, and comprise a wide variety of substances.
These metals will have 1, 2 or 3 electrons in the outer shell. The outer shell of a metal is, therefore, less than half full of electrons. For this reason, metals are more likely to lose electrons to form a full outer shell.
Non-metals are mostly found in groups 5, 6 and 7. These non-metals will have 5, 6 or 7 electrons in the outer shell. The outer shell of a non-metal is, therefore, more than half full of electrons.
For this reason, non-metals are more likely to gain electrons to form a full outer shell. Explanation: The elements on the stair step line are metalloids The elements to the right of the line are non metals.
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