Question

How many electrons must be gained by the element O?
Which 2 I got that but I dont get this one

which noble-gas electron configuration is obtained in this process?
I chose Helium but its wrong I dont know why and other choices are

Xenon, argon, neon, krypton, radon

Answer 1

If you have a periodic table, take a look at Oxygen, atomic number 8.

Answer 2

It's group number (column number) determines how many valence electrons it has in its neutral state. So, a neutral O atom has 6 valence electrons.

Answer 3

However, those main-group nonmetals want to gain atoms to have a stable configuration like the noble gases that are in the far right column. Noble gases have 8 electrons in their valence shells.

Answer 4

In order for O to be like a noble gas, it wants to gain 2 electrons. So, a stable O has 10 electrons, like the closest noble gas, Neon which also has 10 electrons.

Answer 5

Thank you so much! I got it now.