valence electrons these are the electrons on the outermost ring. they are available for bonding. ...
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Valence electrons
These are the electrons on the outermost ring. They are available for bonding.
They can be found by counting the columns on the Periodic Table.
EX: P in group 5A = 5 valence electrons
Common Ion In order to be stable, all elements want an
electron configuration of a NOBLE GAS. They will gain or lose electrons to complete
their outside shell. The periodic table will help you to be able to
predict this.
Atomic Size
Atomic Radius – the distance from the center of an atom’s nucleus to its outermost electron
Atomic Radius Trends:1. Atoms get larger as you
move down a group
WHY? As you move down a group, the valence electrons are on higher principle energy levels which are further from the nucleus
2. Atoms get smaller as you move from left to right across a period
WHY? As you move from left to right across a period there are more protons pulling the electrons in more closely causing it to be smaller
If your trends contradict each other, always use the PRINCIPLE ENERGY LEVEL TO DECIDE!!!
Gettin
g la
rger
Getting larger
Which is the larger atom?
S or O? S because its valence
electrons are on the 3rd EL while O’s are on the 2nd EL
Which is the larger atom?
C or O?C is because they are on
the same EL so the one with fewer protons will be larger (less pull from the nucleus)
Which is the larger atom?
N or S?
S because it is on the 3rd EL while N is on the 2nd EL
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