Question

HEEEEELP ASAPP IM AWARDING 30 points!!!!

An atomic anion with a charge of -2 has the following electron configuration:
1s^22s^22p^63s^23p^6

What is the chemical symbol for the ion?

Answer 1

`\rm S^(2-)`.

Step-by-step explanation:

Based on the electron configuration of this ion, count the number of electrons in this ion in total:

`2 + (2 + 6) + (2 + 6) = 18`.

Each electron has a charge of
`(-1)`.

Atoms are neutral and have
`0` charge. However, when an atom gains one extra electron, it becomes an ion with a charge of
`(-1)`. Likewise, when that ion gains another electron, the charge on this ion would become
`(-2)`.

The ion in this question has a charge of
`(-2)`. In other words, this ion is formed after its corresponding atom gains two extra electrons. This ion has
`18` electrons in total. Therefore, the atom would have initially contained
`18 - 2 = 16` electrons. The atomic number of this atom would be
`16`.

Refer to a modern copy of the periodic table. The element with an atomic number of
`16` is sulphur with atomic symbol
`\rm S`. To denote the ion, place the charge written backwards ("
`2-`" for a charge of
`(-2)`) as the superscript of the atomic symbol:

`\rm S^(2-)`.