### Atomic Numbers and Electron Configurations

Each atom of an element has the following electron configuration:

[tex]1s^2 \ 2s^2 \ 2p^6 \ 3s^2 \ 3p^6 \ 4s^2 \ 3d^{10} \ 4p^6 \ 5s^2 \ 4d^{10} \ 5p^5[/tex]

What is the name of the element?

A. Bromine
B. Iodine
C. Tellurium
D. Xenon



Answer :

To determine the name of the element based on the given electron configuration, follow these steps:

1. Break down the electron configuration:
The given electron configuration is:
```
1s 2s 2p 3s-3p 4s-3d10 4p5s24d105p5
```

2. Identify the highest energy level and the electrons in the outermost shell:
- The configuration ends with "5p5" which indicates 5 electrons in the p orbital of the 5th shell.

3. Locate the element on the periodic table:
- Elements are arranged on the periodic table by increasing atomic number.
- The placement of electrons within an atom's electron shells follows a specific order and these shells are filled according to quantum mechanics principles.
- The element with the configuration ending in "5p5" lies in the 5th period (the row corresponding to the 5th shell), and with 5 electrons in the 5p orbital, it will be in Group 17 (the halogens group).

4. Confirm the element in Group 17 of the 5th period:
- Group 17 elements in the periodic table from 2p5, 3p5, 4p5 to 5p5 are Fluorine (F), Chlorine (Cl), Bromine (Br), and Iodine (I) respectively.
- Since the last configuration component is "5p5", it signifies Iodine (I).

Thus, based on the given electron configuration, the element is Iodine (I).