Question

Which element loses 2 electrons to have a completely filled outermost energy level?
Selenimum (Se)
Strontium (Sr)
Chlorine (Cl)
Sodium (Na)

Answers

GPT-4o mini
To find out which element loses 2 electrons to have a completely filled outermost energy level, we need to consider the electron configurations and oxidation states of the given elements:

1. **Selenium (Se)** - It has six valence electrons in its outermost shell (Group 16). It typically gains 2 electrons to achieve a filled outer shell, not loses.

2. **Strontium (Sr)** - It has two valence electrons in its outermost shell (Group 2). Strontium loses these 2 electrons to achieve a noble gas configuration, which results in a filled outer shell.

3. **Chlorine (Cl)** - It has seven valence electrons (Group 17). Chlorine typically gains 1 electron to complete its outer shell.

4. **Sodium (Na)** - It has one valence electron (Group 1). Sodium loses this 1 electron to achieve a filled outer shell.

Based on this analysis, the element that loses 2 electrons to achieve a completely filled outermost energy level is **Strontium (Sr)**.