Elements and Their Combinations By Mrs. Clark June 26, 2007

Section I: Atoms and Elements

Matter All matter is made up of atoms, which may combine to form molecules. All matter is made up of atoms, which may combine to form molecules. Water Molecules!!!!

An atom is the smallest particle of an element that still has the properties of that element. An atom is the smallest particle of an element that still has the properties of that element. Example: Example: An atom is to an element as gold dust is to a gold nugget.

The parts of an atom include: The parts of an atom include: a central structure called the nucleus which holds the protons and neutrons a central structure called the nucleus which holds the protons and neutrons parts that orbit the nucleus, which are called electrons. parts that orbit the nucleus, which are called electrons.

Organization of Atoms Each element is made of one kind of atom. Each element is made of one kind of atom. Atoms can be organized in sheets or they can bond tightly to other atoms. Atoms can be organized in sheets or they can bond tightly to other atoms.

Elements Alone and Joined Elements join to form compounds. Elements join to form compounds. Compounds are pure substances made of two or more elements that are chemically combined. Compounds are pure substances made of two or more elements that are chemically combined. Table salt is an example of a compound created from the elements sodium and chloride. Table salt is an example of a compound created from the elements sodium and chloride.

“Seeing” Atoms Scientists have developed instruments that can create images of atoms and molecules that show that they are well- organized. Scientists have developed instruments that can create images of atoms and molecules that show that they are well- organized.

Section II: The Periodic Table

What is the Periodic Table? Mendeleyev’s Table Mendeleyev’s Table Elements are arranged by increasing mass. Elements are arranged by increasing mass. Elements with similar properties are in the same columns. Elements with similar properties are in the same columns. Scientists all over the world use this same table. Scientists all over the world use this same table.

Periodic Table Details Chemical symbols: abbreviations of element’s name Chemical symbols: abbreviations of element’s name Metallic Properties: Metallic Properties:MetalsNonmentalsSemimetals Noble gases

Section III: Where are Elements Found?

Element Locations Some elements are rare and others are common. Some elements are rare and others are common. Of the 100 known elements, only 8 of the make up 99% of the Earth’s crust. Of the 100 known elements, only 8 of the make up 99% of the Earth’s crust. Some elements can only exist for a few seconds. Some elements can only exist for a few seconds.

Molecules A molecule is a group of two or more atoms that are chemically joined and that act as a single unit. A molecule is a group of two or more atoms that are chemically joined and that act as a single unit. An example of a molecule is water which is a combination of hydrogen and oxygen. An example of a molecule is water which is a combination of hydrogen and oxygen.

Carbon Compounds “Carbon forms more compounds than all but one other element, hydrogen.” “Carbon forms more compounds than all but one other element, hydrogen.” Hydrocarbons Hydrocarbons Plastics Plastics Carbohydrates Carbohydrates Proteins Proteins Lipids Lipids Nucleic acids Nucleic acids

Unit Questions How are atoms related to matter? How are atoms related to matter? How are atoms related to elements? How are atoms related to elements? How are atoms and molecules related and organized? How are atoms and molecules related and organized?

Bibliography Answers.com Answers.com Atomic structures Atomic structures National Science Foundation National Science Foundation Water molecules Water molecules Smithsonian Gem and Mineral Collection Smithsonian Gem and Mineral Collection Gold bar, coin and dust Gold bar, coin and dust Salem State College Salem State College Scanning electron microscope Scanning electron microscope