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
An element is a substance made from only one type of atom. Remember this definition as you might need it in the exam! For example Carbon is made entirely from carbon atoms. Sodium is made entirely from sodium atoms. Unlike a compound, an element cannot be broken down (chemically) into a more simple substance. The periodic table shows all the elements. Atoms of the same element have the same number of protons and therefore have the same atomic number.