a] Write the trend of atomic size and metallic character along a group and a period in the Modern Periodic Table.
b]"Elements in the periodic table show periodicity of properties." List any four such properties.

Explanation

a) In the Modern Periodic Table both atomic size and metallic character increase down a group and decrease along a period from left to right.
b) Four periodic properties are: (0) Atomic size (i) Metallic character (iii) Chemical reactivity (iv) Electropositivity