Question

6. Why is the second ionisation energy of an atom always gre
7. Why is the second ionisation energy of sodium much great
8. Why does atomic size decrease across a period?
9. Why does atomic size increase down a group?​

Answer 1

7. As Na+ have outer inert shell configuration so it is stable structure. As a result removing another electron requires more energy

8. As effective nuclear charge increases

9. As new shell are added with every new period , their size increases

Answer 2

Answer:

Atoms become ionized (charged) by removal of an electron from the outermost and, and possibly, inner shells. Removal of a second electron can occur from the same outermost shell (magnesium, for example), or from an inner shell (sodium, for example). The energy to remove one electron from a neutral atom is called the first ionization energy, and the energy required to remove the second electron is called the second ionization energy. The second ionization energy is, generally, greater than the first ionization energy.