The electronic configuration of chromium is 1s2 2s2 2p6 3s2 3p6 3d5 4s1.
1s2 2s2 2p6 3s2 3p6 4s1 3d5
The electron configuration of a Copper(II)ion is [Ar]4s0 3d9.
Cr^+2 is the symbol for the Chromium(II) ion
it is a chromium 2 as a good point of reference, and if you don't know the specific charge of an atom, check the ion to which it is bound: the phosphide ion is most commonly charged as a 3- ion because its period is has 3 electrons more than it needs to form a complete octet 2 phosphide ions (per your empirical formula) would have a total ionic charge of 6- if you distribute the (6-) charge evenly through the 3 chromium ions in your empirical formula, then each chromium ion would have to have a charge of 2+ in order for the ionic salt to be neutrally charged. therefore the chromium is chromium (II)
PbCO
1s2 2s2 2p6 3s2 3p6 4s1 3d5
The electron configuration of a Copper(II)ion is [Ar]4s0 3d9.
The electron configuration of copper(II) is [Ar] 3d9 . Copper is [Ar] 3d10 4s1
Cr^+2 is the symbol for the Chromium(II) ion
Cobalt(II) electron configuration is [Ar]3d7.
The electronic configuration of zinc is: [Ar]3d10.4s2
it is a chromium 2 as a good point of reference, and if you don't know the specific charge of an atom, check the ion to which it is bound: the phosphide ion is most commonly charged as a 3- ion because its period is has 3 electrons more than it needs to form a complete octet 2 phosphide ions (per your empirical formula) would have a total ionic charge of 6- if you distribute the (6-) charge evenly through the 3 chromium ions in your empirical formula, then each chromium ion would have to have a charge of 2+ in order for the ionic salt to be neutrally charged. therefore the chromium is chromium (II)
PbCO
Chromium (II) Carbonate. Although I'm not sure Chromium (II) can form, there might be an overall charge on your formula there...
[Ar] 4s2 3d9
The electron configuration of tin(II) cation is [Kr]5s2.4d10.
that is only the electron configuration of nickel, a nickel (II) cation would lose the 2 electrons in the 4s and be 1s2 2s2 2p6 3s2 3p6 3d8