student version of the ions and bonding notes

1. IONS AND BONDING
You will notice that not all the atoms have fully filled outer valence shell from the below
diagram which only shows the number of electrons in the valence shell.
Is there a pattern you see here?
Also notice that the last column (He and Ne) are known as unreactive noble gases, why do
you think that is so?
For the pattern,__________________________________________________________
_______________
For the last column, noble gases have ____________________________, therefore they do
not need to react with other atoms to be stable
Helium does not have 8 electrons in its outer shell, it only has 2 so for helium we say it has
_____________ electronic configuration
Whereas all the other noble gases have 8 electrons in their valence shells and hence, can be
described has having ____________________________.
All atoms like to have octet valence shells, this is very important.
Notice that group 1-3 fall under metals
While group 4 to 8 fall under non-metals

2. Because metals have fewer valence electrons, they prefer to
_____________________________ and enjoy the stability provided by an octet electronic
configuration.
What happens when an atom gives away electrons?
Notice that a sodium atom has 11 protons and that number of protons will never change. But
yet if it has given 1 electron away, how many electrons does it have left? _____
What happens is sodium has 1 more proton than electron, and we know that protons have a
positive charge of +1
And that atom changes from being neutral to
being an______ that has a charge of ______
As the diagram shows, a +1 ion produces
an__________________ that can attract or repel
other charged particles!
Solidify your understanding!
1) what is the ion formed by atoms of
magnesium, boron, and lithium when they lose their electrons?_________________________
For non-metals, they can get aoctet valence shell through 2 ways.

3. The first way is to gain electrons.
Nitrogen needs to gain ____ more electrons to reach octet configuration.
Oxygen needs to gain ____ more electrons to reach octet configuration.
Similar to the example on sodium above, when a non-metal atom such as fluorine atom gains
an electron, suddenly it has 10 electrons and only 9 protons and it has become an ______ with
a charge of -1
Solidify your understanding!
1) what is the ion formed by atoms of chlorine and sulphur when they gain some electrons?
____________________
Draw out the ions formed below.
2) what is the electronic configuration of sulphide (S2-) and oxygen ion?
____________________________________________
But in order to gain electrons, non-metal atoms need to come into contact with ___________
atoms.
The transfer of electrons from metal to non-metal atoms results in ions of
____________________ being formed. Unlike charges cause them to be attracted
____________ to each other.
Obtaining the formula for ionic compounds

4. An ionic compound is always made up of _______ positively charged ions and
_________________ negatively charged ions.
The ________________ of the ions always equal to ______, because the number of electrons
given to form the positive ions is equal to the number of electrons gained to form the negative
ions
3 simple steps to follow to get the formula of an ionic compound
1. Determine the charge of the metal positive ion using the periodic table
2. Determine the charge of the non-metal negative ion using the periodic
table
3. Find the LCM of both charges to get the numbers of each ion in the
compound
Try to find out the formula of 1) Magnesium Chloride and 2) Lithium Oxide
_______________________________________________________
Harder example: try to find the formula of Aluminium Oxide
______________________________________________________
There are also some ions which are not found in the periodic table such as _______________
ion which is NH4+, and ____________ ion which is SO42-, as well as ___________ NO3- and
____________ CO32-.
Find out the chemical formula of ammonium sulphate ___________________
Take note that in your formula, the metal ion should always be first (such as NaCl) and big
ions like sulphate or nitrate should be in brackets like in Mg(NO3)2.
COVALENT BONDING
A covalent bond is defined as the _______________________________ between
_________________. And take note that covalent bonds only apply to non-metal atoms.
Below are a few examples

5. Now you can try to form dot-and-cross diagrams of the following molecules, do not forget to
include a legend, which is worth marks in exams!
1. Br2 2. F2
Some of the harder ones involve many atoms so you need to know which atoms are in the
centre of the molecule. The more number of covalent bonds an atom need to get octet
configuration, the more likely it is to be in the centre bonding to many other atoms.
1. N2 2. NH3 3. CH4
ELEMENTS AND ATOMS CHECKLIST
An atom with more electrons than protons is known as a
1) neutral charged neutron
2) positively charged ion
3) positively charged atom
4) negatively charged ion
Which of the following statement is true?
1) a proton is as heavy as an electron but lighter than an neutron
2) a proton is as heavy as a neutron but lighter than an electron
3) a proton is as heavy as a neutron but heavier than an electron
4) a proton is as heavy as an electron but heavier than a neutron
Atoms are arranged in the periodic table by
1) number of protons and in groups
2) atomic number and in terms of total number of electrons
3) number of groups and protons
4) alphabetical order
What is the maximum number of electrons in the second shell of an atom?
1) 1

6. 2) 2
3) 3
4) 8
What is the difference between a molecule of an element (like H2 gas) and a molecule of a
compound (like H2O)?
__________________________________________________________________________
__________________________________________________________________________
What is the formula of Magnesium Oxide?_________________
Draw the electronic configuration of Helium
Draw a diagram of Sodium Chloride showing the ions of Sodium and Chlorine.
Draw the dot and cross diagram of H2O, together with a legend.
Good job! ^_^

7. Solidify your understanding!
1) what charge
Let me introduce a very important organic molecule called glucose.
It has a chemical composition, meaning it is made up of how many atoms and of which
element, of
6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms