Periodic Table/ElementsAugust 16

1. How many significant figures does 9.0003 have?

2. How many significant figures should the product of 10.3 x 2.3 have?

3. [10 (power 4) + 10 (power 3) ] ÷ 10 (power 2)

Elements

http://vimeo.com/819138

73% Hygrogen

25% Helium

2% everything else

Elements• Periodic Table of the Elements

• The vertical columns of the periodic table are called groups, or families

» Each group contains elements with similar chemical properties

• The horizontal rows of elements in the periodic table are called periods

» Physical and chemical properties change somewhat regularly across a period

Elements• Types of Elements

• Metal is an element that is a good electrical conductor and a good heat conductor

• Properties of metals

» Most are solids at room temperature» Malleable - they can be hammered or rolled into thin

sheets » Ductile - they can be drawn into a fine wire » Conduct electricity and heat well

Alkali Metals:Group 1 in the periodic table.

-soft, white, low-density, low-melting point

-highly reactive metallic elements

-lithium, sodium, potassium, rubidium, cesium, and francium.

-one electron in the outermost energy level

-never found free in nature.

Periodic Table/ElementsAugust 17

1. How many significant figures does 1005.03 have?

2. How many significant figures should the product of 10.30 x 2.30000 have?

3. [10 (power 4) + 10 (power 4) ] x 10 (power 2)

Alkaline Earth Metals: Group 2 in the periodic table.

-metallic elements

calcium, strontium, magnesium, and barium, but generally including beryllium and radium.

-two electrons in the outermost energy level, readily reactive

-never found free in nature.

Transition Metals:

Any of the metallic elements within Groups 3 to 12 in the periodic table

-multiple valences (outermost electron rings)

Elements• Types of Elements

Gold Copper Aluminum

Elements• Types of Elements

• Nonmetal is an element that is a poor conductor of heat and electricity

• Properties of nonmetals

» Many are gases » Solids are brittle» Poor conductors of heat and electricity

Elements• Types of Elements

Carbon Sulfur Phosphorus Iodine

Elements• Types of Elements

• Metalloid is an element that has some characteristics of metals and some characteristics of nonmetals

• Properties of metalloids

» All metalloids are solids at room temperature » Semiconductors of electricity

Halogens: Group 17 in the periodic

table.

-five chemically related nonmetallic elements

-fluorine, chlorine, bromine, iodine, and astatine

-highly reactive and combine readily with most metals and nonmetals to form a variety of compounds

-never occur uncombined in nature.

Elements• Types of Elements

• Noble gases are the elements in Group 18 of the periodic table of the elements

• Properties of noble gases

» Generally unreactive » Gases at room temperature

Elements• Types of Elements

•Lanthanide Metals: Elements representing atomic numbers 57–61 in the periodic table. They are shiny metals, similar in reactivity to alkaline earth metals.

•Actinide Metals: A series of radioactive metallic elements in Group 3 of the periodic table.