Chemistry Vocabulary: Part 4
Chemical Formulas A combination of chemical symbols and numbers to represent a substance Examples H20: Water CO2: Carbon Dioxide NaCl: Salt C6H1206: Sugar
Chemical Equations A representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products Examples C + O2 CO2 2H2 + O2 2H2O
Reactants A substance or molecule that participates in a chemical reaction Examples C + O2 CO2 Reactants 2H2 + O2 2H2O
Products A substance that forms in a chemical reaction Examples C + O2 CO2 Product Zn + 2HCl ZnCl2 + H2
Subscripts A number written below and to the right of a chemical symbol in a formula Tells how many atoms of that element are present Examples CO2 H20 C6H12O6
Coefficients A number that is placed in front of a chemical symbol or formula Tells how many molecules of that substance are present Keeps reaction balanced Example 2H2 + O2 2H2O
Law of Conservation of Mass Mass is neither created nor destroyed in ordinary chemical and physical changes Must start and end with the same amount Example Log + Fire Ashes + Smoke 30 kg 1 kg 28 kg 3 kg