Re: How do you determine which families in the table of elements tend to gain

Hi Tonie,

As a good rule of thumb, elements that tend to gain electrons are at the 
right of the periodic table of elements (before inert gases) and those that 
tend to give electrons are at the left of the periodic table.

A good way to remember this is by looking at the situation of the element in 
the periodic table compared with the situation of the nearest inert gas 
element (helium, neon, argon, krypton, xenon, radon).  All elements will try 
to "look like" its nearest inert gas element.  For exemple, oxygen is 
nearest to neon (two spaces before neon) and it will tend to gain two 
electrons so that it "looks like" neon (i.e. have as much electrons as 
neon).

Sodium which is one space forward of neon will tend to give one electron so 
that it will have the same amount of electrons as neon.

Most of the time, this rule apply although there is some exceptions.

The best way to know which one will tend to give or receive electrons is by 
looking at the element's orbitals although this is a little bit more 
complicated.

I hope this answer helps you a little.

Ciao!

Mike.