I- The Elements: A- Substances that form all matter. 1- Elements are pure substances that can not be broken down by heat, light, or electricity.

I- I- TheThe ElementsElements::

A- A- SubstancesSubstances thatthat formform allall mattermatter..

1-1- Elements are pure substances that can not be broken

down by heat, light, or electricity.

2-2- Elements contain only one type of atom. With the properties of that element.

3-3- Your body contains elements the most abundant being Oxygen, Hydrogen, Carbon, Calcium, Phosphorus, and Nitrogen.

B-B- DiscoveringDiscovering thethe ElementsElements:

1-1- Their are over 109 elements,

90 of them are found in nature.

2-2- In ancient times the people thought their were only 9 elements.

3-3- Marie & Pierre Curie discovered Radium and Polonium in 1898.

C-C- ChemicalChemical SymbolsSymbols

1-1- Is a shorthand form of the element’s name.

2-2- It always starts with a Capital letter. Helium’s =He,

Cobalt’s = Co, Oxygen = O.

3-3- Some elements come from their Latin names for exampleexample

gold = Au aurum lead = Pb plumbum

D- D- DescribingDescribing ElementsElements: : Scientist group elements according to their properties.

1-1- Most elements are metalsmetals or metallicmetallic elements.

a- LusterLuster = Shiny.

b-b- DuctileDuctile = can be drawn (mademade) into a wire.

c-c- MalleableMalleable = can be hammered, rolled, or shaped without breaking. (jewelry)d-d- Solid at room temperature.e-e- Conduct heat well.

2-2- NonmetalsNonmetals or nonmetallicnonmetallic have properties that are opposite of metals.

3-3- MetalloidsMetalloids have properties of metals and nonmetals. GermaniumGermanium, , ArsenicArsenic,, and SiliconSilicon used in computers.

II-II- PhysicalPhysical PropertiesProperties: make a substance identifiableidentifiable.

A-A- Examples =Examples = 1- taste 2- odor

3- hardness 4- color

5- density 6- magnetic 7- boiling & melting point

B-B- Physical ChangePhysical Change: is any change that does notnot alteralter {change} the chemical make-up of a substance.

1-1- Examples=Examples= Dissolving, evaporating, heating,

cooling, size, shape, or phase.

Ice melting Dissolving

EvaporatingFreezing

III-III- ChemicalChemical PropertiesProperties: Describes how two substances react with each other.

A-A-ProducingProducing ChemicalChemical ChangesChanges: Rust and tarnish are new materials with new properties both result from a

chemical change.

1-1- After a chemical change the properties of the original substance is no longer present.

Rust

Tarnish