Explain why Xenon had a lower first ionisation enthalpy than Neon. (3 marks)
Xenon is further down Group 8 of the Periodic Table than Neon, hence has its outermost electrons in higher energy shells further away from the nucleus. Therefore, there are more full intermediate energy levels of electrons in Xenon which are able to shield the outermost electrons more than Neon, such that they feel less of the nuclear charge so are attracted less to the nucleus. Less energy is absorbed to remove an electron and hence Xenon has a lower first ionisation energy.
AM
Related Chemistry A Level answers
All answers ▸Elements in the Periodic Table often show periodic trends. Describe and explain the periodic trend in atomic radius and electronegativity from Na to Cl.
Why does Phosphorus have a higher melting point than Chlorine?
Molecules of hydrogen chloride, HCl, and molecules of fluorine, F2, contain the same number of electrons. Hydrogen chloride boils at –85 °C and fluorine boils at –188 °C.Explain why there is a difference in the boiling points of HCl and F2.
Write an ionic equation, with state symbols, to show the reaction of calcium with an excess of water.