Chapter 3 Section 3 Notes Families of Elements
The Periodic Table • Elements are classified as metals, nonmetals, and metalloids (semiconductors). • Metals are found on the left side of the periodic table, while nonmetals are on the right side. • The only exception is hydrogen, which is the only nonmetal on the left side.
Metals are good conductors of heat and electricity. Metals are shiny solids that can be shaped. Metals are ductile (can be stretched into thin wires). Metals are malleable (can be pounded into thin sheets). A chemical property of metal is its reaction with water which results in corrosion. Characteristics of Metals
Non-metals are poor conductors of heat and electricity. Non-metals are not ductile or malleable. Solid non-metals are dull, brittle and break easily. Many non-metals are gases, but can be solids or liquids. Characteristics of Nonmetals Sulfur
Metalloids (metal-like) have properties of both metals and non-metals. They are solids that can be shiny or dull. They conduct heat and electricity better than non-metals but not as well as metals. They are ductile and malleable. Characteristics of Metalloids
Hydrogen • The hydrogen square sits atop Family 1, but it is not a member of that family; Hydrogen is in a class of its own. • It’s a 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.
The alkali metal family is found in the first column (group) of the periodic table. Atoms of the alkali metals have 1 valence electron. They are extremely reactive because their single valence electron can easily be removed to form a positive ion. Alkali Metals: Group 1
Alkali Metals: Group 1 • They are shiny, have the consistency of clay, and are easily cut with a knife. • They react violently with water. • Alkali metals are never found as free elements in nature; they are always bonded with another element because they are so reactive.
What are the alkali metals? • Lithium (Li) • Sodium (Na) • Potassium (K) • Rubidium (Rb) • Cesium (Cs) • Francium (Fr)
The alkaline-earth metal family is found in the second column (group) of the periodic table. Atoms of Alkaline-Earth metals have 2 valence electrons. Alkaline-Earth Metals: Group 2
They are never found uncombined in nature because they are reactive. To bond, they lose their 2 valence electrons to form cations. Alkaline-Earth Metals: Group 2
What are the alkaline-earth metals? • Beryllium (Be) • Magnesium (Mg) • Calcium (Ca) • Strontium (Sr) • Barium (Ba) • Radium (Ra)
Transition Elements include those elements in groups 3-12. These are the metals you are probably most familiar with: copper, tin, zinc, iron, nickel, gold, and silver. They are good conductors of heat and electricity. Transition Metals: Groups 3-12
Transition Metals: Groups 3-12 • The compounds of transition metals are usually brightly colored and are often used to color paints. • Transition elements typically have 1 or 2 valence electrons, which they lose when they form bonds with other atoms.
Transition Metals: Groups 3-12 • Transition elementshave properties similar to one another and to other metals, but their properties do not fit in with those of any other family. • Many transition metals combine chemically withoxygen to form compounds called oxides. • They are less reactive than the alkali metals and are usually shiny and hard.
The Boron Family is named after the first element in the family. Atoms in this family have 3 valence electrons. This family includes the most abundant metal in the earth’s crust: aluminum. The Boron Family: Group 13
What elements are in the Boron Family? • This family includes: • a metalloid: boron (B) • The rest are metals: aluminum (Al), gallium (Ga), indium (In), and thallium (Tl)
Atoms of this family have 4 valence electrons. The element carbon is called the “basis of life.” There is an entire branch of chemistry devoted to carbon compounds called organic chemistry. The Carbon Family: Group 14
What elements are in the Carbon Family? • This family includes: • Anon-metal: Carbon (C) • Metalloids: Silicon (Si) and Germanium (Ge) • And metals: Tin (Sn) and Lead (Pb)
3 Forms of Carbon • Graphite: a grayish black crystal substance used for pencil lead, oil, and lubricant in machines • Diamond: it is the hardest known natural substance • Fullerenes: a form of carbon that is not graphite or diamond; composed of 60 or more carbon atoms and occur naturally in small amounts; some molecules are often called “Bucky balls”.
The nitrogen family is named after the element that makes up 78% of our atmosphere. Atoms in the nitrogen family have 5 valence electrons. They tend to share electrons when they bond. The Nitrogen Family: Group 15
What elements are in the Nitrogen Family? • This family includes: • The non-metals: Nitrogen (N) and Phosphorus (P) • The metalloids: Arsenic (As) and Antimony (Sb) • A metal: Bismuth (Bi)
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. The Oxygen Family: Group 16
What elements are in the Oxygen Family? • This family includes: • The nonmetals: oxygen (O), sulfur (S), and selenium (Se) • A metalloid: tellurium (Te) • A metal: polonium (Po) Oxygen Atom
Halogens have 7 valence electrons, which explains why they are the most active non-metals. They are never found free in nature. Halogen atoms only need to gain 1 electron to fill their outermost energy level. They react with alkali metals to form salts. Halogens: Group 17
What are the halogens? • Fluorine (F) • Chlorine (Cl) • Bromine (Br) • Iodine (I) • Astatine (At)
Noble Gasesare 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, so they exist in nature as single atoms rather than as molecules. Noble Gases: Group 18
With the exception of Helium, they have 8 valence electrons. Because they do not readily combine with other elements to form compounds, the noble gases are called inert (nonreactive). All the noble gases are found in small amounts in the earth's atmosphere. Noble Gases: Group 18
What are the Noble Gases? • Helium (He) • Neon (Ne) • Argon (Ar) • Krypton (Kr) • Xenon (Xe) • Radon (Rn)
The thirty rare earth elements are made of the lanthanide and actinide series. One element of the lanthanide series and most of the elements in the actinideseries are called trans-uranium, which means “synthetic” or “man-made”. Rare Earth Metals