To determine the noble gas configuration for zirconium (Zr), we need to know its atomic number and then refer to the electron configuration rules based on the periodic table.
1. Identify the atomic number of Zr:
Zirconium (Zr) has an atomic number of 40. This means zirconium has 40 electrons.
2. Find the preceding noble gas:
The noble gas that comes before zirconium in the periodic table is Krypton (Kr), which has an atomic number of 36.
3. Write the noble gas configuration:
Starting from the noble gas krypton, which accounts for 36 electrons, we then need to arrange the remaining 4 electrons for zirconium:
- In the 5th period (or shell), the next orbital to fill after krypton is the 5s orbital.
- The 5s orbital can hold 2 electrons.
- The next sublevel to fill is the 4d orbital, which can hold up to 10 electrons, but there are only 2 electrons left to place here for zirconium.
Hence, the electronic configuration after Krypton is:
- Zirconium: [tex]\([Kr] 5s^2 4d^2\)[/tex]
Therefore, the noble gas configuration for zirconium (Zr) is
[tex]\[ \boxed{[Kr] 5s^2 4d^2} \][/tex]
