Elements lose or gain electrons as needed to have an electron configuration that matches a noble gas?

Question

True or False?
How about this...
Does the Lewis structure for CO2 show that the molecule contains TWO double bonds? Yes or No?

Answer 1

True, and true.

Na loses it's last valence electron to Cl in sodium chloride solution - Na+ has no valence e's in its 4s shell anymore, and chloride now has 8 in its valence shell. Both "look" like noble gases, or are said to have a noble gas configuration.
(does not mean they are inert, though).

In covalent compounds, two elements will share some of their outer e's - those shared e's will spend some time around one element, and some time around the other element. So each element "feels like" it has 8 electrons around it (at least some of the time).

If you know the most stable Lewis structure of CO2, it looks
something like this:

::O=C=O::

The four dots on each O are meant to show 2 electron pairs on each O. Sorry for the lack of available graphics on here.
The two double bonds are covalent. Each bond represents two electrons. So carbon, thru covalent bonding has 4 total bonds (or 8 bonding electrons) shared between it and its neighboring O's. Likewise, each O has 2 pairs of bonding e's and 4 non-bonding e's...total 8.

you will later learn that we call this the Octet Rule.
Google it!

Answer 2

It is true for compounds that follow the Lewis theory. There are compounds like BF3 and SF6 that do not. CO2 is O=C=O, with four more dots around each oxygen to represent the nonbonding electrons ofO.

Answer 3

The compound is neutral, so you know from the formal charge that oxygen has to have 2 bonds in order to be neutral. Carbon has to have 4 bonds to have a formal charge of 0. So if both oxygens have two bonds to carbon...