The Periodic TableThe Periodic Table10/10/1210/10/12

The Periodic TableThe Periodic Table

Describing the Periodic Describing the Periodic TableTable

• It arranges all the known elements in an organized chart. 

• Elements are arranged left to right and top to bottom in order of increasing atomic number and (usually) atomic mass

Types of ElementsTypes of Elements

• 3 main types of elements

–Metals–Metalloids–Nonmetals

• Rows - elements of each row have the same number of energy levels (shells).

• Columns - elements have the same number of electrons in the outermost energy level or shell (one to eight).

PeriodsPeriods

• The different rows of elements are called periods.  – The period number of an element shows

the highest energy level that has at least one electron.

FamilyFamily

• The different columns of elements are called groups or families– Elements in the same family have

similar properties

ElementsElements

• Every element has:

Atomic NumberAtomic Number

  The number of protons in an atom is referred to as the atomic number of that element.

Atomic SymbolAtomic Symbol

The atomic symbol is one or two letters chosen to represent an element.

Ex) H is for Hydrogen

Atomic MassAtomic Mass

The atomic mass is the average mass of an element in atomic mass units ("amu").