El hidrógeno es el elemento químico de número atómico 1, representado por el símbolo H. Con una masa atómica de 1.00784 u es el más ligero de la tabla periódica de los elementos. Por lo general, se presenta en su forma molecular, formando el gas diatómico H₂ en condiciones normales.
The element iodine (I) is important for the fast and hastened metamorphosis of frog-tadpoles. As amphibians, the tadpoles can live in water and land but when they are born they are iodine-deficient. Tadpoles that do not receive ample amount of iodine become tadpoles until the end of their days.
Condensation is when vapor liquidizes and gathers on top of a surface, while boiling is turning a liquid into a gas or vapor. They are opposites. In the first, the molecules of the substance split and separate and increase the volume, while in the second they come together and reduce the volume.