EVERYDAY SCIENCE

Detailed explanation-1: -In a period from left to right the number of valence electrons in the same shell increases due to which the effective nuclear charge increases and therefore atomic size decreases as we move from left to right in a period.

Detailed explanation-2: -Covalent radius increases as we move down a group because the n level (orbital size) increases. Covalent radius mostly decreases as we move left to right across a period because the effective nuclear charge experienced by the electrons increases, and the electrons are pulled in tighter to the nucleus.

Detailed explanation-3: -The number of valence electrons decreases from left to right across each period. The number of valence electrons increases from top to bottom within each group.

Detailed explanation-4: -The correct option is Atomic radius. Concept: Atomic radius: It is the distance from the center of the nucleus to the outermost shell containing electrons. The atomic radius decreases moving from left to right in the Modern Periodic Table.

Detailed explanation-5: -On going from left to right along a period (short period), the valency of elements increases from 1 to 4 and then decreases to 0 (zero).