Question

question 3 1 pts what element does the following noble gas configuration represent? kr 5s² 4d⁷
○ rhodium
○ iridium
○ cobalt
○ chromium

Explanation:

1. First, recall the atomic number of Kr (krypton) is 36.
2. For the electron configuration \([Kr] 5s^2 4d^7\), we calculate the total number of electrons: \(36 + 2+ 7=45\).
3. Now, check the atomic numbers of the options:

• Rhodium (Rh) has atomic number 45.
• Iridium (Ir) has atomic number 77.
• Cobalt (Co) has atomic number 27.
• Chromium (Cr) has atomic number 24.

So the element with atomic number 45 is rhodium.

Answer:

A. rhodium