In: Chemistry
1. As3- > Se2- > Br- > Rb+ > Ge4+
Explanation: In general, positive ions have smaller size than neutral atom and negative ions have lager size than neutral atom i.e., A+ < A < A- .
As negative charge on atom increases, size of atom increases and as positive charge on atom increases, size of atom decreases.
2. Be < Mg < Ca < Sr < Ba
Explanation: Down the group, top to bottom atomic size increases due to addition of new shells.
3. Al > Si> P > S >Cl
Explanation: In period, from left to right atomic size decreases due to increase in nuclear charge
4. Tl > Sb > As > S >F
Explanation: As period number of element increases size also increases due to more number of shells
5. Be shows similar properties with Al due to diagonal relationship
Ca shows similar properties with its 2nd group elements (Mg, Sr, Ba) due to similar electronic configuration
Oxygen shows similar properties with its group 16 elements (S, Se, Te) due to similar electronic configuration