Every species in the Irving-Williams series has this charge.
Every species in the Irving-Williams series has this charge. The two charged species in a Daniell cell both have this charge. In acid, manganese reacts from +7 oxidation state to this oxidation state, where it is colorless. Ions with this charge must be added to coordinate DNA polymerase during (*) PCR. Water hardening agents usually have this charge. Unusually, mercury's lowest oxidation state forms a diatomic ion with this charge. In carbon monoxide, carbon's oxidation state is this value. Nickel and zinc acquire this oxidation state after they lose their 4s electrons. For 10 points, name this value, the charge normally acquired by alkaline earth metals such as magnesium and calcium.
Every species in the Irving-Williams series has this charge.
+2 [or 2+; or positive two; prompt on two]