Families or Groups red group = 1 electron in their outer shell orange group = 2 electrons in their outer shell As you keep counting the colored columns, you add an additional electron. Purple has 8 electrons in its outer shell. (Don’t include the white group) An example of the families are shown here. All elements in the red column have l electron in its outer orbit. When you move on to the other elements in the colored columns an electron is added. The middle columns that are not colored follow a different order. Those we will discuss in another lesson.

Using the Rows Row = “period” not alike in properties all of the rows go from left to right. some squares are skipped in between When looking at the rows of the periodic table, please remember that unlike the columns, they are not alike in properties. The period of an element tells the number of atomic orbitals. All of the elements in the same period have the same number of orbitals.

Using the Rows As a rule. . . . the first element in a period is usually an active solid. the last element in a period is always a noble gas. atomic mass generally increases form left to right there are exceptions The left side of a period is usually an active solid, meaning it is ready to give away one its electrons. The last element on the right side of a period are called the noble gases. They don’t want to gain or lose electrons. They or happy with the 8 in their outer shell. Also, the atomic size decreases from left to right across the row, but the mass increases across a period.

Example Every element in the top row (first period) has one orbital for its electrons. Every element in the second row (the second period) have two orbitals available. Atoms on the left are usually larger and lighter. Atoms on the right are usually smaller and heavier. The periods are color coded to show each row. Every element in the top row (1st period) has on orbital for its electrons. Every elements in the second row (2nd period) has two orbitals for their electrons and we continue down the chart. As said before, the atoms of the elements on the left are usually larger and lighter, and the atoms on the right are usually smaller and heavier.

Metals, Nonmetals, and Semiconductors In general, elements located in the left two-thirds or so of the periodic table are metals. The nonmetals are on the right side of the table. The dividing line between the metals and nonmetals are elements called semiconductors. When looking at several periodic charts, you will see many color variations. Some without color at all. One other way the chart can be color coded to help you understand it is by its element. It will separate the elements into metals, nonmetals, and conductors. The metals and nonmetals are separated, although not in a straight line, by the semiconductors, those elements that sometimes act like metals and sometimes act like nonmetals.

Metals good conductors of heat and electric current freshly cleaned or cut surface will have a high luster, or sheen reflect light solids at room temperature except for mercury (Hg) Ductile - can be drawn into wires Malleable - can be hammered into thin sheets without breaking

Non-Metals gases at room temperature nitrogen and oxygen few solids (sulfur and phosphorus) one liquid (bromine)

metalloid generally has properties that are similar to those of metals and nonmetals under some conditions, a metalloid may behave like a metal. Under other conditions, it may behave like a nonmetal.

A groups… Groups 1A through 7A = representative elements Group 1A elements = alkali metals Group 2A elements = alkaline earth metals Group 7A = halogens Group 8A = noble gases (filled energy levels)

B Group separate the A groups on the left side of the table from the A groups on the right side Transition metals - copper, silver, gold, iron d block Inner transition metals - characterized by f orbitals that contain electrons. f block

highest occupied sublevels

Atomic radius one half of the distance between the nuclei of two atoms of the same element when the atoms are joined one trillion, 1012, picometers in a meter

atomic size increases from top to bottom within a group and decreases from left to right across a period.

Across a period increasing nuclear charge pulls the electrons in the highest occupied energy level closer to the nucleus and the atomic size decreases

ION an atom or group of atoms that has a positive or negative charge form when electrons are transferred between atoms Cation = + charge Anion = - charge

Ionization the energy required to remove an electron from an atom first ionization energy The energy required to remove the first electron from an atom decreases from top to bottom within a group increases from left to right across a period

Group 1A metals lithium (Li), sodium (Na), potassium (K) relatively easy to remove one electron from a Group 1A metal atom difficult to remove a second electron tend to form ions with a 1+ charge

As the size of the atom increases, less energy is required to remove an electron first ionization energy is lower

Cations are always smaller than the atoms from which they form Anions are always larger than the atoms from which they form

Electronegativity the ability of an atom of an element to attract electrons when the atom is in a compound