How is the Periodic Table of Elements Organized

How is the Periodic Table of Elements Organized?

• The Periodic Table of Elements is a way of organizing the elements in relation to each other so it is easy to find elements that have similar properties • It allows scientists to make predictions and explain events

What is a Periodic Table?

What are groups or families? What is represented by the groups on this periodic table?

What are rows or periods ? What represented by the periods on this periodic table?

How would you find the missing data? Group 5 Period 3

What is a Period? • Each row is a period • The elements in each period have the same number of electron shells • The elements in periods DO NOT have similar properties – properties change greatly across every period • The first element in a period is always an extremely active solid • The last element in a period is always an inactive gas 1 st Period = 1 Orbital 2 nd Period = 2 Orbitals 3 rd Period = 3 Orbitals 4 th Period = 4 Orbitals Hint: A period comes at the end of a sentence--a horizontal line.

• • What is a Group or a Family? • • 1 18 2 13 14 15 16 17 Each column is a group or family Each element in a group has the same number of electrons in its outer orbital (valence electrons) Elements in the same group have similar chemical and physical properties Example – Lithium (Li), Sodium (Na), potassium (K), and other members of group 1 are all soft, white, shiny metals Group 1 = 1 valence electron Group 2 = 2 valence electrons Group 8 = 8 valence electrons Except for He, it has 2 electrons Hint: Your Family tree is vertical

What are Properties of Metals? • Good conductors of heat and electricity • Shiny • Ductile (can be stretched into thin wires) • Malleable (can be pounded into thin sheets) • A chemical property of metal is its reaction with water which results in corrosion

What are Properties of Non-Metals? • Poor conductors of heat and electricity • Not ductile or malleable • Solid non-metals are brittle and break easily • Dull Sulfur • Many non-metals are gases

What are Properties of Metalloids? • Metalloids – metal-like • Have properties of both metals and non-metals • Solids that can be shiny or dull • Conduct heat and electricity better than non-metals but not as well as metals Silicon • ductile and malleable

What is Hydrogen? • The hydrogen square sits atop Group 1, but it is not a member of that group • Hydrogen is in a class of its own • Gas at room temperature • It has one proton and one electron in its one and only energy level • Hydrogen only needs 2 electrons to fill up its valence shell

What are Alkali Metals? Group 1 • The alkali family (group 1) is found in the first column of the periodic table • Atoms of the alkali metals have a single electron in their valence shell, in other words, 1 valence electron • Shiny, have the consistency of clay, and are easily cut with a knife • Most reactive metals • React violently with water • Alkali metals are never found as free elements in nature. They are always bonded with another element

What does it mean to be reactive? • Elements are described according to their reactivity • Elements that are reactive bond easily with other elements to make compounds • Some elements are only found in nature bonded with other elements • What makes an element reactive? – An incomplete valence electron level. – All atoms (except hydrogen) want to have 8 electrons in their very outermost energy level (This is called the rule of octet. ) – Atoms bond until this level is complete. Atoms with few valence electrons lose them during bonding. – Atoms with 6, 7, or 8 valence electrons gain electrons during bonding.

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What are Alkaline Earth Metals? (group 2) • Reactive metals that are always combined with nonmetals in nature • Have two valence electrons • Alkaline earth metals include magnesium and calcium, among others

What are Transition Metals? (groups 3 -12) • Less reactive harder metals • These are the metals you are probably most familiar: copper, tin, zinc, iron, nickel, gold, and silver • They are good conductors of heat and electricity. • Have 1 or 2 valence electrons, which they lose when they form bonds with other atoms • Some transition elements can lose electrons in their next-to-outermost level

Transition Elements • Transition elements have properties similar to one another and to other metals, but their properties do not fit in with those of any other group • Many transition metals combine chemically with oxygen to form compounds called oxides

What is the Boron Family? (group 13) • Named after the first element in the group • Atoms in this group have 3 valence electrons • This group includes a metalloid (boron), and the rest are metals • This family includes the most abundant metal in the earth’s crust (aluminum)

What is the Carbon Family? (group 14) • Have 4 valence electrons • Includes a non-metal (carbon), metalloids, and metals • The element carbon is called the “basis of life. ” There is an entire branch of chemistry devoted to carbon compounds called organic chemistry

What is the Nitrogen Family? (group 15) • Named after the element that makes up 78% of our atmosphere • Includes non-metals, metalloids, and metals • Atoms in the nitrogen family have 5 valence electrons -they tend to share electrons when they bond • Other elements in this family are phosphorus, arsenic, antimony, and bismuth.

What is the Oxygen Family? (group 16) • Atoms of this family have 6 valence electrons • Most elements in this family share electrons when forming compounds • Oxygen is the most abundant element in the earth’s crust - it is extremely active and combines with almost all elements

What is the Halogen Family? (group 17) Halogen atoms only need to gain 1 electron to fill their valence shell. They react with alkali metals to form salts. • The elements in this family are fluorine, chlorine, bromine, iodine, and astatine • Very reactive, volatile nonmetals • Halogens have 7 valence electrons, which explains why they are the most active non-metals • They are never found free in nature

What are Noble Gases? (group 18) • Colorless gases that are extremely un-reactive • One important property of the noble gases is their inactivity they are inactive because their outermost energy level is full • Because they do not readily combine with other elements to form compounds, the noble gases are called inert • Includes helium, neon, argon, krypton, xenon, and radon • Found in small amounts in the earth's atmosphere

What are Rare Earth Elements? • The thirty rare earth elements are composed of the lanthanide and actinide series • One element of the lanthanide series and most of the elements in the actinide series are called trans-uranium, which means synthetic or man-made