1.Which has a larger radius Ca atom or Ca+2 ion?
2.Which has a greater radius F atom or F- ion?
3.Which is the correct way of understanding the trend for Ionic radius Vs. Atomic radius?

1.Ca atom has greater radius than Ca+2

2.F- ion has larger radius than F

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72

c) should be the answer.