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

% Abundance of Elements in the Earth's crust

Oxygen (47%)Silicon (28%)Aluminum (8%)Iron (5%)Calcium (4%)Sodium (3%)Potassium (2%)Magnesium (2%)Others (1%)

Elements are organized according to PROPERTIES into

1869Dmitri Mendeleev(Russian chemist)

• Put together the 1st periodic table

1913Henry 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

Ooxygen8

Protonnumber

RelativeAtomic 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) 1st letter of the element’s name :

Hydrogen (H) Nitrogen (N) Sulfur (S)

2) 1st two letters of the element’s name :

Helium (He) Calcium (Ca) Aluminium (Al)

3) 1st and 3rd 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

1 2 3 4 5 6 7 8

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 properties2) 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

CH

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

MgLi

Lithium

Ar

Argon

MOLECULES are made up of TWO or MORE atoms CHEMICALLY combined together.

Chlorine

Cl Cl

Nitrogen

N N

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 (H2) • Nitrogen (N2)• Oxygen (O2)• Fluorine (F2)• Chlorine (Cl2)• Bromine (Br2)• Iodine (I2)

some elements consist of molecules of more than 2 atoms as their smallest particle:

Phosphorus (P4)

P PP

P S

SS S

S S

SS

Sulphur (S8)

Which elements do the particle diagram below represent?