First ionisation enthalpy of two elements X and Y are 500kJ/mol and 375kJ/mol respectively.Comment about their relative position in a group as well as in a period.

Asked by rickykumar00001 | 11th Jun, 2015, 01:32: PM

Expert Answer:

Across a period:
The ionisation energy tends to increase as one moves from left to right across a period.
Since Y has a lower value than X, it will appear to the left of the periodic table and X will appear to the right of the periodic table.
Down a group:
Ionisation energy decreases with an increase in the atomic size i.e. it decreases as one moves down the group.
Therefore X with a higher value than Y will appear at the upper part of the periodic table and Y will appear at the lower part of the periodic table.

Answered by Vaibhav Chavan | 11th Jun, 2015, 06:32: PM