1- why is it difficult to measure the size of an atom? 2-what does the term atomic radius mean?

3-what is Ionization mean?

4- what exception exist in this trend?

5a-What trend evident in atomic radius as you proceed down a group of element?

5b-how does this trend progress as you move across a period?

6- define the term electron shielding?

7a- what effect does electrons shielding have on atomic radius? On ionization energy?

8- when an atom loses an electron, what is it's charge? What do you think happens to the atomic radius of the atom?

9- when an atom gains an electron, what is it's charge? What do you think happens to it's atomic radius?

10- what metal in period 6 has lowest melting point? The lowest boiling point?

Please ASAP