As you move from left to right of the periodic table, the element becomes more negative.
Answer: To show the number of atoms present.
Explanation: As in CO² (Carbon dioxide), there is a small 2 next to the symbol "O" (oxygen) to explain that there are two oxygen atoms.
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p1
Primero realizas la configuración electrónica que es la que te puse allá arriba.
Después miras el nivel en que termina, puede ser 1, 2, 3, 4 etc.
Entonces como el último número de la configuración electrónica es 4, entonces ese es el nivel
Y los electrones de el último nivel son los de Valencia
4s2, 4p1 sumas 2+1 que son los electrones que se encuentran en el último nivel.
por eso hay 3 electrones de valencia.
<span>The energy (E) per photon is expressed by Planck's equation: E = hf, where f is
the frequency and h is Planck's constant, experimentally determined to be
6.625 * 10**-34 joule-seconds. So to find E, we multiply h by the frequency
and obtain E = hf = (6.625 * 10**-34)(7.0 * 10**14) = 46.375 * 10**-20 joule
or in standard notation, E = 4.6375 * 10**-19 joule per photon.
Hope this answers your question.Sorry if I calculated wrong.</span>
1: it is +2
2: it is +6
(Make this brainliest answer please)
