State the number of electrons lost or gained when the following elements form
Ions:
Se
Express your answer as an integer
When the element Se forms an ion, it tends to gain two electrons. Therefore, its loss or gain of electrons can be expressed as -2.
The element Se (selenium) is located in Group 16 (or Group VI) of the periodic table. It has an atomic number of 34, which means it has 34 electrons in its neutral state.
To determine the number of electrons lost or gained when Se forms ions, we need to consider its tendency to either gain or lose electrons. Group 16 elements have a tendency to gain 2 electrons to achieve a stable electron configuration, similar to the nearest noble gas, which in this case is krypton (Kr).
So, when selenium (Se) forms ions, it gains 2 electrons.
Therefore, the number of electrons gained when Se forms ions is 2.
To determine the number of electrons lost or gained when an element forms an ion, you need to know its electron configuration and the desired electron configuration of the ion.
The element in question is Se, which is atomic number 34. The electron configuration of Se is [Kr] 4d10 5s2 5p4. By looking at the periodic table, we can determine that the most common ions formed by Se are Se2- and Se4+.
To find the number of electrons lost or gained when Se forms an ion, we compare the electron configuration of Se with the desired electron configuration of the ion:
1. Se2- ion: The electron configuration of a Se2- ion is [Kr] 4d10 5s2 5p6, which is isoelectronic (having the same number of electrons) as the noble gas krypton (Kr). This means that Se2- has gained 2 electrons to achieve a stable electron configuration. Therefore, when Se forms an Se2- ion, it gains 2 electrons.
2. Se4+ ion: The electron configuration of a Se4+ ion is [Kr] 4d10, which is isoelectronic with the noble gas krypton (Kr). This means that Se4+ has lost 4 electrons to achieve a stable electron configuration. Therefore, when Se forms an Se4+ ion, it loses 4 electrons.
In summary, the number of electrons lost or gained when Se forms ions are as follows:
- Se2- ion: Gains 2 electrons
- Se4+ ion: Loses 4 electrons