Period 3 element pulmonary agent in chemical warfare; however, chlorine is necessary to most forms of life, including humans, in form of chloride ions. Argon has no biological role. Like any gas besides oxygen, argon is an asphyxiant. Period 3 element A period 3 element is one of the chemical elements in the third row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when the periodic table skips a row and
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