What are the possible values of the angular momentum quantum number / ? What does the angular momentum quantum number determine?
Solution The variation in atomic radii can be explained as below Step 1 a)A cation is always lesser in size than the parent atom .This is because an electron is getting removed (no of protons become more than electrons) from parent atom which results in an increase in effective nuclear charge experienced by valence electron. An anion is always larger than the parent atom since an electron is getting added (no of electrons become more than protons) resulting in a decrease in effective nuclear charge experienced by valence electron. Therefore, I- >I >I+ b)As we move down the column in a periodic table size of the atom increases.This is because with increase in principal quantum number n,the number of shells increase resulting in more screening effect.Thus effective nuclear charge will be less and size increases. Therefore, Ca2+ >Mg2+ >Be2+ c) Fe and Fe are formed by loss of 2 and 3 electrons respectively from Fe.Thus Fe and Fe 2+ 3+ has 2 and 3 electrons lesser when compared to the protons in them .When nuclear charge or the number of protons is more, greater would be the pull to the nucleus or closer will be the valence electrons to the nucleus. So size of Fe would be greater followed by Fe and Fe+ 3+ Therefore Fe > Fe >Fe2+ 3+