http://www.sciencegeek.net/APchemistry/APtaters/EquationBalancing.htm
http://education.jlab.org/elementbalancing/
https://www.khanacademy.org/science/chemistry/chemical-reactions-stoichiome/balancing-chemical-equations/e/balancing_chemical_equations
http://phet.colorado.edu/sims/html/balancing-chemical-equations/latest/balancing-chemical-equations_en.html
http://funbasedlearning.com/chemistry/chemBalancer/
http://www.softschools.com/quizzes/chemistry/mass_mole_conversions/quiz1122.html
http://www.chemteam.info/Mole/Grams-to-Moles.html
http://www.sciencegeek.net/Chemistry/taters/Unit4GramMoleVolume.htm
https://www.quia.com/cb/33492.html
https://www.wisc-online.com/learn/natural-science/chemistry/gch1504/stoichiometry
http://www.purposegames.com/game/stoichiometry-game
http://www.softschools.com/quizzes/chemistry/stoichiometry_mass_mass_problems/quiz1196.html
http://education.jlab.org/elementbalancing/
https://www.khanacademy.org/science/chemistry/chemical-reactions-stoichiome/balancing-chemical-equations/e/balancing_chemical_equations
http://phet.colorado.edu/sims/html/balancing-chemical-equations/latest/balancing-chemical-equations_en.html
http://funbasedlearning.com/chemistry/chemBalancer/
http://www.softschools.com/quizzes/chemistry/mass_mole_conversions/quiz1122.html
http://www.chemteam.info/Mole/Grams-to-Moles.html
http://www.sciencegeek.net/Chemistry/taters/Unit4GramMoleVolume.htm
https://www.quia.com/cb/33492.html
https://www.wisc-online.com/learn/natural-science/chemistry/gch1504/stoichiometry
http://www.purposegames.com/game/stoichiometry-game
http://www.softschools.com/quizzes/chemistry/stoichiometry_mass_mass_problems/quiz1196.html