Respuestas
Respuesta:
Each row is a period. The first period consists only of hydrogen and helium, the second of lithium through neon, the third sodium through argon, and so forth. Each period begins with an alkali metal and ends with a noble gas. The f-block elements (lanthanides and actinides) which are usually printed as separate rows under the main body of the table, do not count as periods; they actually belong to the 6th and 7th periods (between La - Hf and Ac -Rf, respectively) but printing them that way would make the table extremely wide.
At present, there are 7 periods of known elements. If we discover/produce any past oganesson, we will need to add another period.
Respuesta:
eso queres oh otra cosa xd Qué es un número decimal periódico?
Expresión decimal periódica es aquélla que tinene un número infinito de cifra decimales, pero de modo que un grupo finito de ellas se repite infinitamente, de forma periódica, por ejemplo 0,333333....., 125,67777777.......
Explicación:
What is a repeating decimal number?
Periodic decimal expression is one that has an infinite number of decimal places, but in such a way that a finite group of them is repeated infinitely, periodically, for example 0.333333 ....., 125.67777777 ..... ..