Answer:- 
.
Explanation:- Atomic number for fluorine(F) is 9 and it's electron configuration is 
. 
is formed when F loses one electron from it's valence shell.
Second shell is the valence shell for fluorine and so it loses one electron from 2p to form and the electron configuration of the ion becomes .
Matter can only me transformed, but not created or destroyed.
Answer:
1.18×10²³ atoms.
Explanation:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms.
From the above concept, 1 mole of sodium also contains 6.02×10²³ atoms.
1 mole of sodium = 23 g.
Thus,
23 g of sodium contains 6.02×10²³ atoms.
Therefore, 4.5 g of sodium will contain = (4.5 × 6.02×10²³)/23 = 1.18×10²³ atoms.
From the above calculation,
4.5 g of sodium contains 1.18×10²³ atoms.
