The Arrangement of Elementsin the Periodic Table

Trends in the Periodic Table and Bonding

The Periodic Table

The periodic table is a very useful arrangement of all of the known chemical elements.It can be used to observe patterns and relationships between different elements, and the table is arranged in several important ways.

Periods

Horizontal rows in the periodic table are called periods.

Elements are arranged in the periodic table in order of increasing atomic number.

Li3

Be4

B5

C6

N7

O8

F9

Ne10

The outer electron shell becomes filled as we move from left to right.

Li2,1

Be2,2

B2,3

C2,4

N2,5

O2,6

F2,7

Ne2,8

The atomic number of the elements increases by one moving left to right along a period.

METALS

NON-

METALS

Metals and Non-Metals

We can divide the periodic table with a ‘staircase’ line to show elements that are metals and non-metals.As we move along a period from left to right we see a shift from metal to non-metal characteristics.

Numbered vertical columns of elements in the periodic table are called groups.

Groups

1 2 3 4 5 6 7 01 2 3 4 5 6 7 0

Some groups are known by special names

Alkali Metals

Transition Metals

Halogens

Noble Gases

1 2 3 4 5 6 7 0

1 3 4 5 6 7 02

Elements in the same group have similar chemical properties

The alkali metals are all soft, very reactive metals.

Li3

Na11K

19Rb37Cs55

They all have one electron in their outer shell and show a gradual trend in both chemical and physical properties as we move down the group

1

1 3 4 5 6 7 02

Elements in the same group have similar chemical properties

The halogens are all very reactive non-metal elements.

They all have seven electrons in their outer shell. The halogens are the only group to contain all three states of matter at room temperature.

F9Cl17Br35I

53At85

7

1 3 4 5 6 7 02

Elements in the same group have similar chemical properties

The noble gases are all unreactive gaseous elements. He

2Ne10Ar18Kr36Xe54

They all have a full outer electron shell and are all odourless, colourless monatomic gases.

Rn86

0