Ionic bonding is bonding between a metal and a non metal. When writing the formula, you need to write the metal first.
Then, write the non metal. There is a special way to actually show the way to do thing. At this level, you should know how
to do Rutherford-Bohr and Lewis diagrams. Write the atoms in the order they appear. Then, write diagrams of each atom
with only the valence shell electrons in a ring around the elements. Then, show with an arrow, that how ever many electrons
from the metal, are transferring over to the non metal. The compound should have a total charge of 0 as the metal will give
up electrons, and the non metal will gain electrons from the metal. We know this from our knowledge of the periodic table
and the trends that exist in it. You would write the equation like this:
Ba + O --> Ba(2+)O(2-)
Note: There are no brackets around the numbers. That is just to show that the numbers should be superscript. Both atoms
will have brackets around them and the non metal will have 8 electron dots around it in the bracket to show it has a stable
octet. So, it would look like this:
Ba + O --> [Ba](2+)[O](2-)
Remember again that there brackets around the numbers are strictly to let you know that it should be superscript, meaning
higher than the base number itself, looking somewhat like an exponent.
This is an electron dot diagram, and the ways in which to complete them correctly.
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Covalent is between non metals and non metals. Instead of transferring electrons, the two non metals share electrons
in an outer valence shell. For example, look at CH4. Carbon has 4 electrons that participate in covalent
bonding. When you draw Lewis Dot diagrams, you draw 1 dot on each sides, for a total of 4 sides, like a square. Once you've
made it around all sides, continue until the atom's outer valence has been completed. Here is an example:
Note that the little circles represent valence electrons in Carbon's valence shell. Carbon's outer valence is 4. So,
it can share each electron with each Hydrogen, to completely bond. If there was a pair of electrons, like this:
the pair can't participate in covalent bonding. So, only the three single electrons can covalent bond. The pair is called
a lone pair.
After going through this step, you must show a diagram with the central atom and lines to each atom it is bonding with.
Note: The atom with the highest bonding capacity, in this case Carbon, is written in the middle, and each bonding
atom around it, in a certain geometric shape. However, do not be too worried about the geometric shape of the diagram at this
point in time.
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