El concepto “tetravalencia del carbono” se refiere a: La formación del metano
La capacidad del carbono para formar cuatro enlaces
El número atómico del carbono
La energía empleada por el carbono para unirse a cuatro hidrógenos
El número de electrones configurados en los niveles 1 y 2 de energía.
cual es ??

odds are decent that your handwriting right now looks a little bit different than it did five years ago, and will look different again in five more. when i look back through my notebooks from middle school to now, i see a long, slow progression from meticulous and teeny letters to bigger, sloppier ones, plus a few side detours: sometime in high school, for example, i decided those loopy cursive lowercase f’s were just the coolest, adopting them as the lone rep for cursive in my otherwise all-print handwriting.

explanation:

the correct answer is:

a. formation of precipitation