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 that cannot be decomposed into simpler substances. This was the first useful definition of element, because it allowed elements to be distinguished from other substances experimentally.ocabulary allotrope atomic number atomic weight atoms Dalton's atomic theory isotope mixture nucleus substance An element is a type of matter composed of atoms that all have exactly the same positive charge on their nuclei.