The Periodic Table Is a table of elements arranged in order of increasing atomic number and upward and downward trends.

Is a also known as the number of protons in an atom of an element. The Atomic Number Is a also known as the number of protons in an atom of an element.

Periods Are the rows that go across on the table and represents the ENERGY LEVELS of an atom.

Groups Are columns and represent the same number of OUTER ENERGY LEVEL ELECTRONS that dictate similar physical and chemical properties.

Properties such as: Conductivity Reactivity Boiling & Melting Point Density M/V Ionization Energy

The Periodic Table is arranged into four main groups: Metals-low number of outer shell electrons Nonmetals-high number of outer shell electrons Metalloids-semiconductors Noble Gases-unreactive *atom arrangement depends on the outer shell electrons

Main Group Elements Groups 1, 2, & 13-18 have regular electron configurations. They are the representative elements. Main Group Elements 1A-8A Transition Elements 1B-8B

Four groups within the main group have special names: GROUP 1 ALKALI METALS GROUP 2 ALKALINE EARTH METALS GROUP 17 HALOGENS GROUP 18 NOBLE GASES

METALS Are groups 1-12 and some elements in groups 13-16. These are good conductors of electricity and except for Mercury are solids at room temperature.

GROUP 1ALKALI METALS Are called as such because they react with WATER to produce alkaline solutions and because they have metallic properties. They are very soft and can be cut with a knife. A newly cut surface is shiny, but dulls quickly when exposed to oxygen and water in the air.

ALKAI METALS cont… Alkali Metals have to be kept in kerosene (heating oil) to isolate it from reacting in the air. They are highly explosive. Alkali metals react vigorously with cold water forming hydrogen gas and a very alkaline solution. They are good conductors of electricity because of their electron configuration.

ALKALI METALS continued They have only one electron in their outer shell. By losing this electron, the element becomes stable like a noble gas *This is why these metals are very reactive. This one electron wants to get away from the atom and reactive any atom around it.

Plasmas-the fourth state of matter At high temperatures, alkali metals become plasmas, the fourth state of matter. They are made of ions, electrons and neutral particles. Ions are atoms that have lost or gained electrons

Plasma continued… As electricity flows through the ions, electrons and neutral particles, electrons are transferred to higher energy levels and a photon of light is emitted (given off) as the electron returns to its original energy state or ground state. In fog lights, sodium plasma emits a yellow glowing light. These are in many cars sold today.

Atom emitting a photon

FINAL NOTE Group 1 metals are so reactive they are not found in nature by themselves and have to be produced in a laboratory for commercial or educational purposes.

GROUP 2 ALKALINE EARTH METALS These metals are harder, denser, and have higher melting points than alkali metals. These metals are less reactive than those in group one. In reactions with other metals, these metals lose two electrons to become a noble gas. All elements will lose or gain electrons to achieve stability.

ALKALINE EARTH METALS continued… One of the most common alkaline earth metals is CALCIUM found in limestone and marble and and essential to good bone structure and health. CALCIUM is a metal

GROUP 17 HALOGENS These are nonmetals that combine with metals to produce SALTS. The word halogen means “salt former” in Greek. NaCl is sodium chloride and ordinary table salt. *The halogens are the MOST REACTIVE GROUP of the nonmetals.

HALOGENS continued… When halogen atoms react chemically, they often require ONE electron to achieve stability. They are said to achieve the configuration of a noble gas. All elements want to achieve a noble gas configuration. The halogens exist in all 3 states of matter at STP.

HALOGENS

GROUP 18 NOBLE GASES These gases were formerly known as inert gases because the were thought to be completely unreactive due to having a full outer shell of electrons. This means that all the noble gases have EIGHT electrons in their outer shell. However, Xenon has been prepared as XeF2. HELIUM has only TWO electrons, but is considered to have a full outer shell.

HELIUM

HYDROGEN In a Class of its Own Is considered in a class of its own and is the MOST COMMON and NUMEROUS element in the universe. It was the first element to form in the universe. It contains ONE PROTON & ONE ELECTRON only.

HYDROGEN

GROUPS 3-12 TRANSITION METALS These metals have electrons used for bonding in more than one energy level. Therefore, they DO NOT exhibit regular electron configurations like the Main Group Elements who only have electrons for bonding in the outer shell. Bonding electrons are called VALENCE ELECTRONS.

GROUPS 13-16 THE OTHER METALS These metals exhibit regular electron configurations and exhibit all the characteristics of metals, such as luster, malleability, electrical and heat conductivity to various degrees. They are all solids, have high densities, and are opaque.

THE METALLOIDS These semimetals as their known, conduct electricity, but not as well as metals. By adding trace metals, semiconductors are useful as transistors and in other electronic devices like computers and calculators. They contain both properties of metals and nonmetals.

GROUPS 14-16 THE NONMETALS These nonmetals as their called are poor conductors of electricity and heat. They are brittle and are not able to be hammered or rolled. They also lack luster. They are found in solid and gas states at STP.

RARE EARTH METALS Thirty rare earth elements are composed of the Lanthanide and Actinide series. Most elements in the Actinide series and ONE element in the Lanthanide series are TRANSURANIUM. Transuranium means synthetic or manmade. These manmade elements are made in a particle accelerator in a laboratory.

VOCABULARY ION-an atom that has gained or lost electrons ANION-an atom that has gained electrons. CATION-an atom that has lost electrons. ENERGY LEVEL-where electrons spin around an atom. They are given numbers to identify each of the seven levels an atom may contain. ORBITAL-are areas or regions in an atom where there is a high likelihood of finding an electron. Orbitals contain zero, one or two elcctrons. One or more orbitals can be found in each of the seven energy levels.

Atom showing Energy Levels

CONCEPTS TO KNOW All physical and chemical properties of the periodic table are explained by the atom itself and the number of electrons contained in the outer shell. The Periodic Table was formulated by Dmitri Mendelev and illustrates the atom’s periodic nature. Periodic means repeating. The properties of the atoms repeat similarities when ranked from lowest to highest by atomic number.

CONCEPTS TO KNOW continued The atom has a very tiny dense nucleus with a very large diameter where electrons are thought to reside. Electrons spin around the nucleus in pairs called orbitals. Orbitals spin at various distances from the nucleus. Those distances are determined by how much energy the electron has and is assigned an energy state Each energy state is an assigned energy level.

Atom showing tiny nucleus and orbitals

Atom with Orbitals

FINAL NOTE METALS lose electrons to be stable. NONMETALS gain electrons to be stable.