Chemical Language
Knowledge of the Chemical Language is essential if a true understanding of this subject is to develop: A few key questions need to be answered:
1. The first question every student should ask themselves is: " What information can I get from the Periodic Table?".
The Periodic Table is a list of elements (all made up of many atoms of that element) arranged into Groups (vertical columns) and Periods (horizontal rows) placed in order of INCREASING ATOMIC NUMBER (that's an exam answer!!). Metallic elements are on the left of the ZIG-ZAG line, non metallic elements are on the right of the ZIG-ZAG line.
Remember if an element is in Group 1; this means that atoms of that element have one electron in their outer shell: if an element is in Group 2 of the Periodic Table then atoms of that element have two electrons in their outer shell. This pattern is followed for all groups in the Periodic Table; so if an element is in Group 7; atoms of that element have 7 electrons in their outer shell............think now about atomic structure and watch a short YouTube clip; DOT and CROSS diagrams.
It is also worth noting that atoms of elements in Group 1 have a Valency of 1; those in Group 2 have a Valency of 2; those in Group 3 have a Valency of 3, those in Group 4 have a Valency of 4, those in Group 5 have a Valency of 3, those in group 6 have a Valency of 2 and those in Group 7 have a Valency of 1. Now look at a LIST OF IONS; What is the relationship between Valency and the charge on ions? Valency is the number of charges on an ion. Can you use valency or ions or both to write formulae? The answer is both.
Now think about Periods; if an element is in Period 2 then each atom of that element has two electron shells, if an element is in Period 3, an atom of that element has 3 electron shells...and the pattern continues.
2. The next big question you should ask yourself is: "What is Chemistry all about-do I we really need it in life?"
The answer is simple; you do need it and the reason you are able to sit and read this website is because the atoms of elements that make up your body and the clothes you are wearing have made an energy based decision to get themselves into the most stable (unreactive) state that they can. Some elements are stable as atoms, some are more stable as ions (often metal atoms lose electrons to become more stable positive metal ions; sometimes non metal atoms gain electrons to become more stable negative non metallic ions); visit YouTube: ATOMS v IONS; some atoms of elements are more stable when they form diatomic molecules (molecules made of two non metallic atoms of the same element, chemically combined). Another way for atoms to become more stable is for them to bond with atoms of other elements to form molecular compounds (two or more non metallic atoms can share electons to form covalent bonds and form stable molecules like water).
3. How can predictions be made about; whether and how atoms of elements will react?
a) The reactivity series of metals is also useful to know with the non metallic elements Carbon and Hydrogen inserted:
MOST REACTIVE ATOMS OF ELEMENTS K, Na, Ca, Mg, Al, (C), Zn, Fe, Sn, Pb, (H), Cu, Hg, Ag, Au LEAST REACTIVE ATOMS OF ELEMENTS
HOW WILL YOU REMEMBER THIS?
b) and being able to work out the electron configuration of atoms is essential.
In conclusion: atoms become more stable by gaining a full outer shell of electrons by either gaining or losing electrons to form ions; ions can then interact with one another or if they are non metallic atoms of elements by sharing their outer electrons with either another atom of their own to form diatomic moleules or by sharing their outer electrons with atoms of dfferent elements to form new molecular compounds.
Now try and answer the following:
1. How are elements arranged on the Periodic Table? 2. What is an element? 3. What is a molecule? 4. What is a compound? 5. What is a mixture? 6. How do I find out the Valency of an element? 7. Can I use Valency to write formulae? 8. Do I know the symbols for common ions? 9. Can the symbols of common ions be used to write formulae? 10. What does the word monatomic mean? 11. What does the word diatomic mean? 12. Can you name three common diatomic molecules? 13. Can you list the reactivity series for atoms of metallic elements and place the non metallic elements of Carbon and Hydrogen into it? 14. Do you know the solubility of substances in water. If not follow the link SOLUBILITY RULES. This will become very useful.
In summary; having a knowledge of the symbols for elements, the ions for elements, the ions for hydroxides, sulphates, carbonates and nitrates and certain common diatomic molecules (hydrogen, oxygen and nitrogen gases) and molecular compounds (e.g water, carbon dioxide and carbon monoxide), will help with equation writing, which will in turn help with the understanding of amount of substance (mole) ratios, allowing for correct amount of substance (mole) calculations.