JEE Main 17 March 2021 Shift 2 Solved Paper

Common positive oxidation states for an element with atomic number 24 , are +2 to +6
Chromium ( Z=24 )
Electronic configuration: [Ar] 4s13d5 It has five electrons in 3d-subshell and one electron in 4s-subshell. Thus, chromium metal has six valence electrons.
Chromium can lose some or all of its valence electrons to form ions with different oxidation states. Thus, chromium shows the oxidation states of +1, +2,+3,+4,+5 and +6 respectively.
The most common oxidation states of chromium are +2,+3 and +6.