2 hydrogen and 2 chlorine on the reactant side(left of the arrow)
There is only 1 H and 1Cl on the products side so the balanced equation would be;
H2 + Cl2 —> 2 HCl
Isotope- variation of an element
Sixteen- atomic number of oxygen
D. The total number of atoms when glucose and oxygen react stays the same when carbon dioxide and water are produced. The conservation of the mass is a fundamental law of chemistry and physics. It indicates not only that during any experiment, including if it involves a chemical transformation, the mass is conserved, but also that the number of elements of each chemical species is conserved. Like any law of conservation it is expressed by a conservation equation.