Why does the periodic table look like this?

He

Li

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Ti Pb Bi Po At Rn

Fr Ra Ac Rf Ha

H

Be

N OCB F Ne

Why does the

periodic table look like this?

The Periodic Table of Elements has the design it does because

• the elements in the table have common properties and

• the structure of atoms making up the elements have common characteristics.

vertical columns are called Groups and demonstrate several common trends.

Groups

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Rd Ag Cd In Sn Sb Te I Xe

Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Fr Ra Lr

Atoms increase in size descending through a group

Atoms in a group have same number of valence electrons so they behave similarly

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Rd Ag Cd In Sn Sb Te I Xe

Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Fr Ra Lr

Many groups have special names that describe their characteristics:

Alkali Metals

Halogens

Alkaline Earth MetalsTransition Metals

Noble Gases

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Rd Ag Cd In Sn Sb Te I Xe

Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Fr Ra Lr

Horizontal rows are called Periods and demonstrate trends as well.

Atoms increase in size ascending through a period

Atoms in a period have the same number of electron shells

Periods

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Rd Ag Cd In Sn Sb Te I Xe

Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Fr Ra Lr

The Periodic Table is broken into three basic categories of elements:

MetalsNonmetals

Metalloids

The table also gives you details about specific elements.

47

Ag

Silver

107.87

Symbol

Name Atomic Mass

Atomic Number