7. Which one of the following pairs of elements would have a (i) N or o
(ii) For CI
8. The size of an anion is larger than that of its parent atom w
that of its parent atom. Explain.
9. Explain why the first ionization energy of Na is lower than that
energy of Na is higher than that of Mg?
10. What prompted Bartlett to discover noble gas compound?
11. Explain the trends in chemical properties of noble gases.
12. Write the uses of the following:
(1) Helium
(ii) Argon
(iii) Neon​