Periodic table so on). Each shell consists of one or more subshells (named s, p, d, f and g). As atomic number increases, electrons progressively fill these shells and subshells more or less according to the Madelung rule or energy ordering rule, as shown in the diagram. The electron configuration for neon, for example, is 1s 2s 2p. With an atomic number of ten, neon has two electrons in the first shell, and eight electrons in the second shell; there are two electrons in the s subshell and six in the p subshell. In periodic table terms, the first time an electron
Element-reactant-product table reaction equation is not balanced, it needs coefficients to show equality. Here is an example with the separation of natural gas from hydrochloric acid using magnesium.<br> Mg + HCl = MgCl + H <br>Here is the element-reaction-product table:<br> From this table we see that the number of hydrogen and chlorine atoms on the product's side are twice the number of atoms on the reactant's side. Therefore, we add the coefficient "2" in front of the HCl on the products side, to get our equation to look like this:<br> Mg + 2HCl = MgCl + H<br> and our table looks like