ANSWER:
The melting and boiling points increase in order of increasing atomic number.
The size of the nucleus increases in order of increasing atomic number.
Ionization energy decreases in order of increasing atomic number.
Electronegativity decreases in order of increasing atomic number.
Electron Affinity decreases in order of increasing atomic number.
The reactivities decrease in order of increasing atomic number.
EXPLANATION:
NAME MELTING POINT BOILING POINT
Fluorine -220 -188
Chlorine -101 -35
Bromine -7.2 58.8
Iodine 114 184
Melting and Boiling points increase as shown above.
NAME COVALENT RADIUS IONIC RADIUS
Fluorine 71 133
Chlorine 99 181
Bromine 114 196
Iodine 133 220
Size increases as shown above.
NAME FIRST IONIZATION ENERGY
Fluorine 1681
Chlorine 1251
Bromine 1140
Iodine 1008
Ionization energy decreases as shown above.
NAME ELECTRONEGATIVITY
Fluorine 4
Chlorine 3
Bromine 2.8
Iodine 2.5
Electronegativity decreases as shown above.
NAME ELECTRON AFFINITY
Fluorine -328.0
Chlorine -349.0
Bromine -324.6
Iodine -295.2
Electron affinity decreases as shown above.
REACTIVITY
The reactivities of the halogens decrease. This is due to the fact that atomic radius increases in proportion with an increase of electronic energy levels. This decreases the pull for valence electrons of other atoms, minimizing reactivity.
