Periodic Table/Elements August 16 How many significant figures does 9.0003 have? How many significant figures should the product of 10.3 x 2.3 have? [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/Elements August 17 How many significant figures does 1005.03 have? How many significant figures should the product of 10.30 x 2.30000 have? [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.