Question

The decrease in atomic size is not much prominent across which block?​

Answer 1

Answer:

Because of this, 85% of the attraction force produced by z* is counterbalanced by interelectronic repulsion therefore only 0.15 more z* decreases in size which is very small so almost equal size and no significant decrease in size treds in priods of the d block.

Explanation:

Answer 2

The decrease in atomic size is not much prominent across which block because:

• In the modern periodic table, elements are arranged in increasing order of their atomic number. rows in which elements arranged horizontally are known as periods whereas vertical arrangement is groups.
• In the modern periodic table, there are 18 groups and 7 periods, which determine the properties of elements.
• The periodic table contains four blocks s, p, d and f.
• Atomic size increases down the group because nuclear charge decreases and the number of shells increases down the group.
• In the d block, a decrease in atomic size is not occurring much because of lanthanoid contraction.
• Due to lanthanoid contraction, 4d and 5d have nearly the same size because of counterbalancing effect of poor shielding of d orbitals and increase of shell.
• Poor shielding decreases the size whereas increase in shell increases size, which balances each other.