ERREAKZIO KIMIKOAK
Sarrera: https://www.youtube.com/watch?v=kth4IkORe7k&feature=fvw
Adibideak: https://www.youtube.com/watch?v=78G3nlJL4iE&feature=related
Estekiometria egiten hasteko: https://www.youtube.com/watch?v=FQpav9lOgBE&feature=related