Question

Give the trend for atomic radius across a period and down a group, and explain each of these trends in terms of attraction, repulsion, and effective nuclear charge.

Answer 1

Atomic radius decreases across a period due to increase in attraction between nucleus & electrons in the valence shell, thus increasing effective nucleus charge.

Atomic radius increases down the group due to addition of one shell at each successive step

Hope this helps!

Answer 2

Step-by-step explanation:

In a periodic table when we move down the group atomic radius increases .This is because:

• On moving down the group new shells or energy levels are added to an atom.
• By the addition of new shells valence electrons of the element gets far away from the nucleus.
• As electrons are far way from the nucleus they will experience less attraction towards nucleus, less effective nuclear charge
• Due to increase in size less electronic repulsion will be present between the electrons .

In a periodic table when we move across the period atomic radius decreases .This is because:

• On moving left to right the shell or energy level remains the same.
• The new electron enters in the same shell with increase in nuclear charge by one unit.
• By this, more force of attraction and more effective nuclear charge is experienced by the electrons with high electronic repulsion among them selves.