CrO₄²⁻: Cr = +6, O = −2
NO₃⁻: N = +3, O = -2
CaO; Ca = +1, O = −1
Zn: Zn = 0
H₂O; H = +1, O = −2
Sr²⁺: Sr = +2

CrO₄²⁻: Cr = +6, O = −2
NO₃⁻: N = +5, O = -1
CaO; Ca = +1, O = −1
Zn: Zn = 0
H₂O; H = +1, O = −1
Sr²⁺: Sr = +2

CrO₄²⁻: Cr = +4, O = −1
NO₃⁻: N = +5, O = -2
CaO; Ca = +2, O = −2
Zn: Zn = 0
H₂O; H = +1, O = −1
Sr²⁺: Sr = +2

CrO₄²⁻: Cr = +6, O = −2
NO₃⁻: N = +5, O = -2
CaO; Ca = +2, O = −2
Zn: Zn = 0
H₂O; H = +1, O = −2
Sr²⁺: Sr = +2