For example, 2 + 3 + 5 = 10 is an equation. Chemistry A written representation of a chemical reaction, in which the symbols and amounts of the reactants are separated from those of the products by an equal sign, arrow, or a set of opposing arrows. For example, Ca(OH) 2 + H 2 SO 4 = CaSO 4 + 2H 2 O, is an equation.
an element is a pure substance that is made from a single type of atom elements are the building blocks for all the rest of the matter in the world examples of elements include iron oxygen hydrogen gold and helium
A chemical element or element is a chemical substance consisting of atoms having the same number of protons in their atomic nuclei (i.e. the same atomic number, Z).s a special case, the three naturally occurring isotopes of the element hydrogen are often specified as H for 1 H (protium), D for 2 H (deuterium), and T for 3 H (tritium). This convention is easier to use in chemical equations, replacing the need to write out the mass number for each atom.