Question

define ionisation energy and mention its trend in periodic table with reasons​

Answer 1

$\huge\mathfrak {AnSwer:-}$

⭕️ Energy required to remove an electron from an isolated gaseous atom is called ionisation enthalpy.

⭕️ Periodic variation:

• ⭕️ Enthalpy of ionisation of elements increase across the period.

• ⭕️This is due to decrease in atomic size and increase in nuclear charge.

⭕️ Ionisation enthalpy decrease down group

• ⭕️This is due to increase in atomic size and increase in magnitude of screening or shielding effect of inner electrons.