Step-by-step explanation:
1 As you go down a group, the atomic radius of the elements increases.
2 This trend is caused by the increase in the number of electron shells as you go down a group. As more electron shells are added, the distance of the outermost electrons from the nucleus increases, resulting in a larger atomic radius.
3 (a) S
(b) Na
(c) B
(d) Br
(e) Mg
(f) O
4 Ionization energy is the amount of energy required to remove an electron from an atom or an ion.
5 Sodium has a low ionization energy because its outermost electron is only weakly attracted to the nucleus. The electron is therefore relatively easy to remove, resulting in the formation of a 1+ ion. Magnesium, on the other hand, has a higher ionization energy because its outermost electron is more strongly attracted to the nucleus. It takes more energy to remove this electron, resulting in the formation of a 2+ ion.
6 (a) Li
(b) Na
(c) Cl
(d) Li
(e) Ca
(f) Ar
Ionization energy generally increases as you go across a row in the periodic table. This is because the electron shielding effect decreases and the nuclear charge increases as you go from left to right in a row. The electron is therefore more strongly attracted to the nucleus, requiring more energy to remove it.