Some images are from www.chem4kids.com

www.middleschoolscience.com 2008

Essential Questions:

What determines where an element is placed on the Periodic Table of Elements?

Which properties determine if an element is a Metal, Nonmetal or Metalloid?

Periodic table organizes elements according to their PROPERTIES

• Arranged in rows and columns

• Metals are on the left

• Non-metals are on the right

Families or Groups on the Periodic Table

• Elements on the periodic table can be grouped into families bases on their chemical properties.

• Each family has a specific name to differentiate it from the other families in the periodic table.

• Elements in each family

react differently with

other elements.

Electrons & the Periodic Table

Elements are grouped because they have similar properties

In some groups, the elements all have the same number of valence electrons in their atoms

• The vertical (up and down) columns of the periodic table (there are 18) are called groups or families.

• Elements in the same group or family have similar characteristics or properties.

Groups or Families of Elements

ALKALI METALSGroup 1• Hydrogen is not a member, it is a

non-metal• 1 valence electron • Soft and silvery metals• Very reactive, esp. with water• Conduct electricity

Image: http://www.learner.org/interactives/periodic/groups2.html

ALKALINE EARTH METALSGroup 2• 2 valence

electrons• White and

malleable• Reactive, but less

than Alkali metals• Conduct electricity

Groups 3-12

Groups 3-12

The Transition Metals are less reactive than Groups 1 & 2 because they don’t lose their valence electrons as easily.

TRANSITION METALSGroups in the middle

• Good conductors of heat and electricity.

• Some are used for jewelry.

• Can bond with many elements in a variety of shapes.

Silver and Gold are Transition Metals.

BORON FAMILY

Group 13

• 3 valence electrons

• Most are metals

• Boron is a metalloid

CARBON FAMILY Group 14• 4 valence

electrons• Contains metals,

metalloids, and a non-metal Carbon (C)

NITROGEN FAMILY Group 15• 5 valence electrons• Can share

electrons to form compounds

• Contains metals, metalloids, and non-metals

OXYGEN FAMILY Group 16• 6 valence

electrons• Contains metals,

metalloids, and non-metals

• Reactive

HalogensGroup 17• 7 valence electrons• All are non-metals• Very reactive are

often bonded with elements from Group 1

Noble GasesGroup 18• Exist as gases• Non-metals• 8 valence = Full octet• Helium (He) has only 2

electrons in the outer shell = Full 1st Energy level that only holds two electrons

• Not reactive with other elements

Rows

• The horizontal rows of the periodic table are called periods.

• Elements in a period are not alike in properties.

• The period number tells us how many energy levels each atom contains.

Rows

• Atomic mass (number of protons) increases from left to right across a period.

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