ThePeriodic Table of Elements

Periodic Table of Elements

Periodic Table

• Organization:– Groups or families: 18 columns – elements that have

many similar chemical & physical characteristics

– Periods: do not have similarities; total of 7 periods (rows) in the table (Increase Energy as Levels go Down)

• Go left to right on the periodic table, and the atomic number (protons) increase

• Total of 109 known elements on the table

Metals

• Metals are the majority of the elements on the periodic table of elements

• Metals are good conductors of electricity, usually have a high density

• Most are shinny, and malleable (the ability to be shaped)

• Include such things are calcium, sodium, titanium, etc.

Alkali Metals

• Elements with only 1 electron in the outermost energy level

• Located in Group 1 of periodic Table• Do not have complete outer energy levels;

therefore, they are not stable or inert• They tend to lose their one valance

electron very easily to become stable• HIGHLY REACTIVE

Transition Metals

• Less reactive than Alkali metals and Alkaline Earth metals

• Shiny metals

• Good conductors of electricity

• Examples are iron and copper

Nonmetals

• Have the opposite properties from metals

• Have a dull luster and are usually brittle

• Low densities and melt at a lower temperature

• Do not conduct electricity well

• Examples: sulfur, noble gases, etc.

Metalloids

• The elements in the staircase (just to the left and right of the staircase line)

• Have properties of both metals and nonmetals• They are solids that conduct heat and electricity

better than nonmetals but not as well as metals• Example is silicon which is a semiconductor (it is

somewhere between a conductor and insulator of electricity)

Noble Gases

• Located in the far right in Group 18

• Tend not to combine with other elements

• Outermost energy level is holding the maximum number of electrons possible

Noble Gases

• They are stable or inert

• Elements that are NOT noble gases, do not have all electrons filled in outer energy levels

• Elements with completely full energy levels are extremely stable and tend to react with almost nothing else

Halogens

• Group 17

• Elements with 7 valance electrons

• Not stable or inert (since the outermost energy level is not filled)

• Halogen elements tend to gain one electron from other atoms so they can become more stable

Vocabulary

• Atomic mass units – unit used to measure the mass of subatomic particles

• Atomic number – the number of protons in an atom

• Families – columns of elements in the Periodic Table

• Metalloids – an element that has properties of both metals and nonmetals

Vocabulary

• Metals – elements which are good conductors of electricity, are malleable, and are shinny

• Nonmetals – elements that are poor conductors of electricity, are brittle, and have low melting points

• Periodic table – chart that organizes all known elements according to atomic number