The element that corresponds to the electron configuration 1s²2s²2p⁶3s²3p⁶4s¹3d⁵ is chromium (Cr).
To understand why this is the case, let’s break down the electron configuration:
- 1s²: 2 electrons in the first shell (s orbital).
- 2s²: 2 electrons in the second shell (s orbital).
- 2p⁶: 6 electrons in the second shell (p orbital).
- 3s²: 2 electrons in the third shell (s orbital).
- 3p⁶: 6 electrons in the third shell (p orbital).
- 4s¹: 1 electron in the fourth shell (s orbital).
- 3d⁵: 5 electrons in the third shell (d orbital).
When counting all these electrons, we find the total is 24. Each element on the periodic table corresponds to a specific atomic number based on the total number of electrons. The atomic number 24 corresponds to chromium.
Additionally, chromium is known for having an electron configuration that is slightly different from what you might expect. Typically, you might expect the 4s sublevel to fill before the 3d. However, chromium is actually more stable with a single electron in the 4s and a half-filled 3d subshell, which is reflected in its electron configuration. Thus, the correct answer is chromium (Cr).