<span>C is the correct answer. Elements in the periodic table are grouped based on having similar properties. For example, the noble gases are all non-reactive and non-metallic. The electronic structure of an atom is the way the electrons are arranged within it, and this affects where they are located in the periodic table. The number of electrons in an element is the same as its group number in the periodic table (with the exception of Group 0).</span>
The atoms and ions that have the similar electron configuration are named isoelectronic. The common ions of representative elements are isoelectronic with a noble gas. When forming ions, transition metals be unable to find their valence s-sublevel electrons before they lose their d-sub level electrons.
Answer:
B) 2Crº + 6e- --> 2Cr3+
Explanation:
The process of oxidation is where electrons are lost. Thus, out of the 2 ions that change charge(Cr and Cu), we must choose the one where the oxidation number increases(which means electrons are lost). Cr goes from an oxidation number of 0 to an oxidation number of 3+, while Cu goes from an oxidation number of 2+ to 0. Thus, we are looking at the half reaction for Cr. Half reactions never have subtracting electrons, so the answer must be B. I am assuming that last plus should be a -->
