[ad_1]
Atoms have electron shells with a certain number of electrons, and the outermost shell is the valence shell, which determines chemical reactions. Elements in the same group have the same number of electrons available for reactions. Charge number determines an atom’s charge during ionic reactions. Transitional elements can bond with different elements, and group IV elements tend to form covalent bonds.
One of the most fundamental driving forces of chemical reactions is the electronic bonds formed between atoms. Electrons are negatively charged particles that orbit the nucleus of an atom in shells. Each electron shell of an atom has a certain number of electrons which it conserves whenever possible even if it unbalances the net charge of the atom; electrons and protons individually have the same amount of electric charge. The amount of charge of a given atom is expressed in superscript to the right of the element name; for example Na1+. The number and superscript is known as the charge number.
The outer electron shell of an atom is called the valence shell and is the basis of chemical reactions. Each shell has a varying number of electrons: the innermost shell contains two electrons, the next contains eight, and the next contain 18. The charge number arises from the natural tendencies of atoms to have a complete valence shell, whether to gain or lose electrons. Elements are organized in the periodic table into groups based on the number of electrons in their valence shells. If two elements are in the same column, or group, on the periodic table, they have the same number of electrons available for chemical reactions.
With the exception of hydrogen, the elements on the left side of the table – groups I and II – are alkali metals and alkaline earth metals. They have practically empty valence shells, with only one or two electrons respectively. Groups III to VII are nonmetals. Group III has three electrons, group IV has 4, and so on. Noble gases such as neon, radon and xenon have full valence shells and therefore do not react with other elements.
The charge number determines what kind of charge an individual atom will have if it gains or loses electrons during an ionic chemical reaction. For example, sodium loses an electron when it reacts with chlorine; chlorine gains an electron. Their respective charges are 1+ and 1-. In their natural state, all elements have a zero charge number because there is no gain or loss of electrons.
The transitional elements in columns 3 to 12 of the periodic table can bond with different elements. Therefore, their billing numbers will vary. Group IV elements, such as carbon, have a charge number of 4+/4-. They tend to form covalent bonds with other atoms, where electrons are shared rather than transferred.
[ad_2]