The Periodic Table (Your new best friend!!)

The Periodic Table The Periodic Table is a list of all the known elements. It is organized by increasing atomic number. As you move from the left to the right, the elements become less metallic with the far right side of the table consisting of nonmetals.

The Periodic Table Elements in the middle of the table are called “transition” elements because they are changed from metallic properties to nonmetallic properties. Elements who touch the “zigzag” line are called metalloids because they have both metallic and nonmetallic properties.

Describe how to read the periodic table: Every table has:

Describe how to read the periodic table: Atomic Symbol: One or two letters chosen to represent an element. These symbols are used every where in the world Usually, abbreviation of the element or the abbreviated Latin name of the element.

Describe how to read the periodic table: Atomic Number The number of protons in an atom identifies the element. 

Describe how to read the periodic table: Atomic Mass: The average mass of an element Measured in atomic mass units ("amu”) Is an average of all the isotopes of an element. Mass Number: protons + neutrons = Mass Number Is always a whole number.

Groups of the Periodic Table

Families on the Periodic Table The table is arranged in vertical columns called “groups” or “families” The horizontal rows are called “periods.” Elements in each vertical column or group have similar properties

Families on the Periodic Table Elements on the periodic table can be grouped into families bases on their chemical properties. Each family has a specific name to differentiate it from the other families in the periodic table. Elements in each family react differently with other elements.

Groups Vertical columns on the PT Elements in the same group… have the same number of electrons in their outer shell (Valence Electrons) behave similarly Examples: Group 1 = 1 valence electron Group 2 = 2 valence electrons Group 13 = 3 valence electrons Group 15 = 5 valence electrons

Alkali Metals Group 1, Metals 1 Valence Electron Very reactive – they really want to bond Elements in this group: Lithium (Li) -Rubidium (Rb) Sodium (Na) -Cesium (Cs) Potassium (K) -Francium (Fr) Hydrogen is not a member, it is a non-metal ----- Meeting Notes (9/15/14 14:10) ----- hi

Alkaline Earth Metals Group 2, Metals Group 2, Metals 2 Valence Electrons Less reactive than group 1, but still want to bond Elements Beryllium (Be) -Strontium (Sr) Magnesium (Mg) Calcium (Ca) -Radium (Ra) Group 2, Metals 2 Valence Electrons Less reactive than group 1, but still want to bond Elements Beryllium (Be) -Strontium (Sr) Magnesium (Mg) -Barium (Ba) Calcium (Ca) -Radium (Ra)

Halogens Group 17 Nonmetals 7 Valence Electrons Very reactive – want to bond Elements: Fluorine (F) -Iodine (I) Chlorine (Cl) -Astatine (At) Bromine (Br)

Noble Gases Group 18 Nonmetals, gases Have full outer shells Will NOT react Elements: Helium (He) - Krypton (Kr) Neon (Ne) - Xenon (Xe) Argon (Ar) - Radon (Rn)

Transition Metals Contain most of the more common metals – gold (Au), silver (Ag), platinum (Pt) Can hold more than 8 electrons in their shells (up to 32!)

Check your understanding This element has 3 valence electrons. What group does it belong to? ________________ This element reacts very similarly to Lithium when added to water. Which group does it belong to? _________________ Which period on the PT is Germanium(Ge) found in? _________________ Give an example of an element with 6 valence electrons. __________________ Name an element that is not reactive. _________________ Which group of elements on the PT does not react? _________________________

Metals, Nonmetals and Metalloids

Coloring in the Periodic Table

Notice the difference between the appearance of the metals and nonmetals. Click here for a better view of each of the elements.

Physical properties of METALS Metals are SOLIDS at room temperature. (except mercury) Metals are HARD. (except Lithium, Potassium, Sodium, Mercury)

Physical Properties of METALS Metals are shiny. (Have “luster”) LUSTER – the way an object’s surface reflects light

Best conductors: silver and copper When you leave a spoon in a cup of hot drink, the bit poking out of the drink gets hot. Why? Conduction! METALS are the best conductors of heat. This is because the electrons in metals move more freely than in non-metals, allowing the heat energy to travel across the metal. For example, when the spoon touches the hot drink, the heat from the drink excites the electrons in the metal, and the electrons transfer the energy from one electron to another, carrying the heat all the way up the spoon quickly. Best conductors: silver and copper

Physical Properties of METALS Metals are good conductors of electricity. Copper, silver, and gold are good electrical conductors. In a conductor, electric current can flow freely. Since metals have free electrons, they can carry a charge easily. Copper Wiring

Physical Properties of METALS Metals are malleable (bendable). Ex. Aluminum Foil

Physical Properties of METALS Metals are ductile. Ductility or ductile – can be drawn (pulled) into a wire

Examples of Metals Potassium, K reacts with water and must be stored in kerosene or oil Copper, Cu, is a relatively soft metal, and a very good electrical conductor. Zinc, Zn, is more stable than potassium Mercury, Hg, is the only metal that exists as a liquid at room temperature

NONMETALS To the right on the PT (except Hydrogen) Non metals may be solids, liquids or gases. Examples: Solids – Carbon, Sulfur, Phosphorus Liquid – Bromine Gases – Oxygen, Hydrogen, Nitrogen

Physical Properties of NONMETALS Nonmetals have a dull luster. (They are not shiny!) Example: Phosphorus

Physical Properties of NONMETALS Nonmetals are insulators. They do not conduct electricity or heat well. The atoms in nonmetals do not have loose electrons. Therefore, when electricity, or something hot touches a non-metal, the energy does not move quickly through the material. What would you rather stir a hot pot with—a wooden spoon or a metal spoon?

Physical Properties of NONMETALS Nonmetals are soft and brittle (fragile). Example: Sulfur

Examples of Nonmetals Microspheres of phosphorus, P, a reactive nonmetal Sulfur, S, was once known as “brimstone” Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure

An interesting element: Carbon Ever break the point of your pencil? That’s because it’s made of graphite, a substance made up completely of Carbon—a brittle nonmetal. Carbon atoms in graphite However diamonds, the hardest material of all, are made of the same element: Carbon. Look at how the carbon atoms are arranged in diamonds—why do you think diamonds are harder than graphite? You may also want to discuss how we are using carbon to create new materials such as nanotubes, or discuss buckeyballs.

Metalloids are found along the stairstep.

METALLOIDS Elements classified as Metalloids have physical properties of both metals and non-metals. Some are shiny, some are dull, they are somewhat malleable and ductile, and can conduct heat and electricity at a lesser level than metals. SILICON ARSENIC BORON

METALLOIDS Some metalloids are useful semiconductors, which are used in electronics (radio, computer chips, telephones, etc.) They are useful because they conduct just the right amount of electricity or heat.

Silicon, Si – A Metalloid Silicon has metallic luster Silicon is brittle like a nonmetal Silicon is a semiconductor of electricity Other metalloids include: Boron, B Germanium, Ge Arsenic, As Antimony, Sb Tellurium, Te

Some show the mass number and atomic number in nuclear symbol form 23 Na atomic number 11 Atomic Symbols

Isotopes Atoms that have the same number of protons but different numbers of neutrons

Describe Isotope Example: http://education.jlab.org/glossary/isotope.html

Isotope Questions Naturally occurring carbon consists of three isotopes, 12C, 13C, and 14C. State the number of protons, neutrons, and electrons in each of these carbon atoms. 12C 13C 14C 6 6 6 #p+ _______ _______ _______ #no _______ _______ _______ #e- _______ _______ _______

Answers 12C 13C 14C 6 6 6 #p+ 6 6 6 #no 6 7 8 #e- 6 6 6

Some quick questions An atom has 14 protons and 20 neutrons. A. Its atomic number is 1) 14 2) 16 3) 34 B. Its mass number is C. The element is 1) Si 2) Ca 3) Se D. Another isotope of this element is 1) 34X 2) 34X 3) 36X 16 14 14

IONS IONS are atoms or groups of atoms with a positive or negative charge. Taking away an electron from an atom gives a CATION with a positive charge Adding an electron to an atom gives an ANION with a negative charge. To tell the difference between an atom and an ion, look to see if there is a charge in the superscript! Examples: Na+ Ca+2 I- O-2 Na Ca I O

Forming Cations & Anions A CATION forms when an atom loses one or more electrons. An ANION forms when an atom gains one or more electrons F + e- --> F- Mg --> Mg2+ + 2 e-

PREDICTING ION CHARGES In general metals (Mg) lose electrons ---> cations nonmetals (F) gain electrons ---> anions

Learning Check – Counting State the number of protons, neutrons, and electrons in each of these ions. 39 K+ 16O -2 41Ca +2 19 8 20 #p+ ______ ______ _______ #no ______ ______ _______ #e- ______ ______ _______