Cr+ has what valence electron
The correct answer and explanation is:
The Cr+ ion has 5 valence electrons.
Explanation:
Chromium (Cr) is located in Group 6 of the periodic table. Its neutral atomic configuration is [Ar] 3d⁵ 4s², meaning it has 6 valence electrons. However, when chromium loses an electron to form the Cr+ ion, one of the outermost electrons is removed.
In this case, chromium first loses an electron from the 4s orbital. This is because the 4s orbital is at a higher energy level than the 3d orbitals. After the loss of one electron, the electron configuration of Cr+ becomes [Ar] 3d⁵, leaving 5 electrons in the 3d orbital.
The key point is that the 4s electrons are lost first when forming positive ions. Thus, even though the neutral atom has 6 valence electrons, the Cr+ ion retains only 5, which are found in the 3d subshell. This configuration makes the Cr+ ion have a stable, half-filled 3d subshell, which is a relatively stable configuration.
In conclusion, Cr+ has 5 valence electrons after losing an electron from its outer 4s orbital.