We are going to study the first elements of the Periodic table. The elements in Nature tend to the minimum energy. This is achieved by having the "s" and "p" layers full or empty, but never "half-way". Therefore, the elements will tend to give in or gain electrons to achieve it.

Move the mouse over the elements to display their electronic configuration.
How many electrons are missing or exceeding to the situation of a closed shell?



Can you relate this fact to the periodic properties of the elements?
Let's study element by element:



Element
Leftover
Missing
Comment

H

0

1

With 1 electron the 1s shell is completed. This element tends to gain 1 electron.

13
It is high. It is difficult to remove an electron from it. It would end up empty of electrons

2.2
It is relatively high. It attracts electrons to itself with relative ease to complete the shell 1s

He

0

0

It already has the 1s layer complete. This element does not react. It is inert.

24
It is the highest. It is almost impossible to remove an electron from it. This would leave layer 1 half complete.

0.0
It is null because it never does bond to other atoms.

Li

1

7

By giving up 1 electron its 1s shell is complete. This is much easier than gaining 7 electrons to complete the 2s2p shell. This element easily give up 1 electron.

6
It is very low. It is very easy to remove 1 electron from it. This is achieved by emptying layer 2 completely but maintaining layer 1 complete.

1.0
It is very low too. It does not have any need to attract electrons since it's a more stable situation to lose them.

Be

2

6

Giving up 2 electrons it ends up with shell 1 complete. This is much easier than gaining 6 electrons. This element tends to give up 2 electrons.

9
It is low. It is easy to rip off it 2 electrons. This is achieved by emptying layer 2 and leaving the shell 1 complete.

1.6
It is relatively low. It has almost no desire to attract electrons since it is more favorable for it to lose them.

B

3

5

By giving up 3 electrons you are left with complete shell 1. This is much easier than gaining 5 electrons. This element tends to give up 3 electrons.

8
It is low. It is easy to rip off 2 electrons. With this, layer 2 is emptied and layer 1 is left complete.

2.0
It is low. Although it does not have much desire to attract electrons since it is more favorable for it to lose them, a certain tendency to the contrary is beginning to be detected.

C

4

4

It is equally easy or difficult to give up 4 electrons to empty shell 2 or gain them to complete it. This element is very versatile and can act in either way.

12
It is high. It's starting to be difficult to get electrons out of it.

2.6
It is high. It easily attracts bonding electrons to itself to complete shell 2.

N

5

3

It is easier to gain 3 electrons than to give up 5. This element tends to gain 3 electrons to complete shell 2.

14
It is even higher. It is even more difficult to tear electrons from this element.

3.1
It is high. A little more than in C. It easily attracts bonding electrons to itself to complete layer 2.

O

6

2

It is much easier to gain 2 electrons than to give up 6. This element tends to gain 2 electrons to complete shell 2.

13
Similar to the previous one.

3.5
It is high. A little more than in N. It easily attracts electrons to itself to complete shell 2.

F

7

1

It is much easier to gain 1 electron than to give up 7. This element tends to gain 1 electron to complete shell 2.

17
It is very high. It is difficult to remove an electron from it. This would leave layer 1 half completed.

4.0
The highest. With this it expresses its need to attract a single electron to complete shell 2.

Ne

0

0

You now have layers 1 and 2 completed. This element does not react. It is inert. Its behavior is analogous to He.

22
It is almost the highest. It is almost impossible to remove an electron from it. This would leave layer 2 lacking one electron to be complete.

0.0
It is null because it never does bond to other atoms.

Na

1

7

Giving up 1 electron it ends up with shells 1 and 2 complete. This is much easier than gaining 7 electrons. This element tends to give up 1 electron. Its behavior is analogous to Li.

5
It is very low. It is very easy to remove 1 electron from it. This allows it to empty layer 3 completely but keeps layers 1 and 2 complete.

1.0
It is very low. It has almost no need to attract electrons since it is more favorable for it to lose them.


Mg


2


6

Giving up 2 electrons shells 1 and 2 end up complete. This is much easier than gaining 6 electrons. This element tends to give up 2 electrons. Its behavior is analogous to Be.

7
It is low. It is easy to rip off 2 electrons. This makes it possible to empty layer 3 and make layers 1 and 2 complete.

1.2
Ii is very low. It has almost no need to attract electrons since it is more favorable for it to lose them.

Al

3

5

Giving up 3 electrons it keeps shells 1 and 2 complete. This is much easier than gaining 5 electrons. This element tends to give up 3 electrons. Its behavior is analogous to B.

6
It is low. It is easy to rip off 3 electrons. This makes it possible to empty layer 3 and leave complete layers 1 and 2.

1.5
It is relatively low. It has almost no need to attract electrons since it is more favorable for it to lose them.

Si

4

4

It is equally easy or difficult to give up 4 electrons to empty shell 2 or gain them to complete it. This element is very versatile and can act in either way. Its behavior is analogous to C.

8
It's low. It is relatively easier to remove 4 electrons from it than from C because Si's outermost electrons are further away that C's. This makes it possible to empty layer 3 and leave layers 1 and 2 complete.

1.8
It is relatively low. It has almost no need to attract electrons since it is more favorable for it to lose them.

P
 

5
 

3

It is easier to gain 3 electrons than to give up 5. This element tends to gain 3 electrons to complete shell 3. Its behavior is analogous to N.

11
It is high. It's starting to be difficult to get electrons out of it.

2.1
It is low. Although it does not have much need to attract electrons since it is more favorable for it to lose them, a certain tendency to the contrary is beginning to be detected.

S
 

6
 

2

It is much easier to gain 2 electrons than to give up 6. This element tends to gain 2 electrons to complete shell 3. Its behavior is analogous to O.

11
It is high. It's starting to be difficult to get electrons out of it.

2.6
It is high. It easily attracts electrons to itself to complete shell 3.

Cl
 

7
 

1
 

It is much easier to gain 1 electron than to give up 7. This element tends to gain 1 electron to complete shell 3. Its behavior is analogous to F.

13
It is even higher. It is even more difficult to tear electrons from this element.

3.3
It is high. Much larger than in the S. It easily attracts electrons to itself to complete shell 3.

Ar
 

0
 

0

You now have layers 1, 2, and 3 complete. This element does not react. It is inert. Its behavior is analogous to Ne.

16
It is one of the highest. Is almost impossible to remove an electron from it. This would leave layer 3 lacking one electron to complete.

0.0
It is null because it never does bond to other atoms.