CLASSIFYING MATTER ELEMENTS

 CANNOT be broken down into simpler substances by CHEMICAL methods.  About 110 elements are discovered by scientists. About 90 occur naturally while the rest are man made.  All matter is made up of

 Elements are organized according to PROPERTIES into 1869 Dmitri Mendeleev (Russian chemist) Put together the 1 st periodic table 1913 Henry Moseley (British physicist) Improved it into today’s version

Each element is given : 1) CHEMICAL NAME 2) SYMBOL (1 or 2 letters) 3)PROTON (ATOMIC) NUMBER 4)RELATIVE ATOMIC MASS 16 O oxygen 8 Proton number Relative Atomic Mass Symbol Name

When elements are discovered, they are named: 1)After people : Einsteinium (Es), Curium (Cm), Mendelevium (Md) 2)After places: Americium (Am), Polonium (Po) 3)Derived from Latin /Greek : Helium ~ from Greek word helios (sun) Fluorine ~ from Latin word fluere (to flow)

Chemical symbols usually consist of: 1)1 st letter of the element’s name : Hydrogen (H)Nitrogen (N) Sulfur (S) 2)1 st two letters of the element’s name : Helium (He)Calcium (Ca) Aluminium (Al) 3)1 st and 3 rd letters of the element’s name: Magnesium (Mg) Chlorine (Cl) Zinc (Zn)

4) Original Latin /Greek name of element: Sodium ~ Natrium (Na) Iron ~ Ferrum (Fe) Potassium ~ Kalium (K) Gold ~ Aurum (Au) Silver ~ Argentium (Ag) Lead ~ Plumbum (Pb) Mercury ~ Hydragyrum (Hg) Tin ~ Stannum (Sn)

WOMANIUM (WO) Physical properties: Generally soft and round in form. Boils at nothing and may freeze any time. Very bitter if not used well. Chemical properties: Very active and highly unstable. Possesses strong affinity with gold, silver, platinum, and precious stones. Violent when left alone. Turns slightly green when placed next to a better specimen. Usage: An extremely good catalyst for dispersion of wealth. Caution: Highly explosive in inexperienced hands! Attention: New Additions to Periodic Table

MANIUM (XY) Physical properties: Solid at room temperature but gets bent out of shape easily. Difficult to find a pure sample. Due to rust, aging samples are unable to conduct electricity as easily as young samples. Chemical properties: Attempts to bond with WO any chance it can get. Also tends to form strong bonds with itself. Becomes explosive when mixed with Childrium for prolonged period of time. Usage: Possibly good methane source. Caution: In the absence of WO, this element rapidly decomposes and begins to smell. Attention: New Additions to Periodic Table

 PERIODIC TABLE is arranged in order of increasing atomic number.  VERTICAL columns are called  HORIZONTAL rows are called

There are 8 in the periodic table. Elements in the same group share SIMILAR chemical properties.

Across a from left to right, there is a gradual change of : 1)Chemical properties 2)Metallic to non-metallic properties

 Elements in the periodic table can also be classified into :

1.Shiny 2.Ductile 3.Malleable 4.Sonorous 5.High density 6.High melting points 7.Good conductors of heat & electricity 8.Mostly solids (except mercury) * For the uses of various metals, refer to text book.

1.Dull 2.Brittle 3.Low density 4.Non-ductile 5.Non-sonorous 6. Low melting points 7. Poor conductors of heat and electricity 8. Can be solids, liquids or gases * For the uses of various non-metals, refer to text book.

Substances that are with properties of both metals and non-metals 1.Solids 2.Ductile 3.Malleable 4.Can be shiny or dull 5.Conduct heat & electricity better than non-metals but not as well as metals

 is represented by drawing a circle with the element’s symbol written in it. E.g. Carbon atom C H Hydrogen atom Cl Chlorine atom  ATOMS are the SMALLEST particles of an element that can take part in a chemical reaction.

 All atoms of a given element are IDENTICAL and different from the atoms of any other element. identical iron atoms.

 MOST elements consist of ATOMS as their smallest particles. E.g. all the metals and noble gases.  However, some elements consist of MOLECULES as their smallest particles. E.g. all the non-metals. Magnesium Mg Li Lithium Ar Argon

 MOLECULES are made up of TWO or MORE atoms CHEMICALLY combined together. Chlorine Cl Nitrogen NN  Molecules of elements consist of the SAME type of atoms joined together.

 Some elements consist of molecules of 2 atoms as their smallest particle. (Diatomic elements) E.g. Hydrogen (H 2 ) Nitrogen (N 2 ) Oxygen (O 2 ) Fluorine (F 2 ) Chlorine (Cl 2 ) Bromine (Br 2 ) Iodine ( I 2 )

 some elements consist of molecules of more than 2 atoms as their smallest particle: Phosphorus (P 4 ) PP P P S SS S S S S S Sulphur (S 8 )

 Which elements do the particle diagram below represent?