Answer:
1) B
2) D
3) A
4) Ga
5) K
6)Po
7) Atomic size increases down the group
8) B<Al<Ga<In<Tl
9)Se<C<Ga
10) ionization energy is the energy required to remove electrons from the outermost shell of an atom.
Explanation:
In the periodic table, the properties of elements reoccur ''periodically'' throughout the table, hence the name 'periodic table'.
Ionization energy increases across the period hence the noble gas He has the highest ionization energy.
Since ionization energy increases across the period, group 1 elements possess the lowest ionization energy.
Since atomic size increases down the group and decreases across the period, gallium is smaller than indium, potassium is smaller than caesium, polonium is smaller than titanium and iodine is larger than bromine.
This explanation above justifies the order of increasing atomic radius of group 13 elements shown in answer number 8 above.
Since atomic size decreases across the period, the order of increasing atomic size shown in answer number 9 above is correct.
Ionization energy is the energy required to remove electrons from the outermost shell of an atom.
