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
(Äl'É-mÉnt) A substance that cannot be broken down into simpler substances by chemical means. An element is composed of atoms that have the same atomic number, that is, each atom has the same number of protons in its nucleus as all other atoms of that element. Today 115 elements are known, of which 92 are known to occur in nature, while the remainder have only been made with particle accelerators.