Atoms, Elements and the Periodic Table. Periodic Table of Elements.
Periodic Table/Elements August 16
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Transcript of Periodic Table/Elements August 16
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
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.