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)

Using the Rows

• Row = “period”

• not alike in properties

• all of the rows go from left to right.– some squares are skipped in between

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

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.

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.

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